Vitamins & Health

Antioxidant Supplementation May Improve Fertility in Men

2011-11-28T17:42:00.001-08:00

A new scientific review concludes that use of antioxidant supplements by men could help improve their partner’s chances of conceiving.

Read more about this research below.

It has been suggested that between 30% to 80% of male subfertility cases are a result of damaging effects of oxidative stress on sperm. Oral supplementation with antioxidants may improve sperm quality by reducing oxidative stress.

Researchers recently reviewed 34 randomized, controlled trials that included a total of 2,876 couples undergoing assisted reproductive techniques (ART) such as in vitro fertilization. Most men in these studies had reduced sperm counts and motility. Scientists included randomized controlled trials comparing any type or dose of antioxidant supplement (single or combined) with placebo, no treatment, or another antioxidant, and taken by the male partner of a couple seeking fertility assistance. The outcomes were live birth, pregnancy, miscarriage, stillbirth, sperm DNA damage, sperm motility, sperm concentration, and adverse effects.

Antioxidant use was associated with a greater likelihood of pregnancy and live birth compared to a placebo or no treatment. Improvements in sperm motility and concentration were also observed in association with antioxidant use in trials that evaluated these effects. No harmful effects associated with antioxidant treatment were noted.

Although more head-to-head comparisons are needed to understand whether any one antioxidant performs better than others, current evidence suggests that antioxidant supplementation in subfertile males may improve the outcomes of live birth and pregnancy rate for subfertile couples undergoing cycles of assisted reproductive treatment.

Showell MG, et al. Antioxidants for male subfertility. 2011. Cochrane Database Syst Rev 1:CD007411.

Multivitamins May Lower Preeclampsia Risk

2011-11-28T17:36:00.001-08:00

Results from a large study show that regular use of a multivitamin supplement in the months before and during pregnancy may reduce the risk of preeclampsia by as much as 71%.
Read more about this research below.

Preeclampsia is a complication of pregnancy associated with high blood pressure and excessive swelling of arms and legs. If untreated, the condition can progress to eclampsia, a condition characterized by seizures, coma, and possible death of the mother or child. In a recent study, lean women who used multivitamins before and during their pregnancies had their risk of preeclampsia reduced by 45-71 percent.

Research included 1,835 pregnant women enrolled in the Pregnancy Exposures and Preeclampsia Prevention Study. All women were at less than 16 weeks' gestation and were asked whether they regularly used multivitamins or prenatal vitamins in the past six months. Women that reported use of a multivitamin or prenatal during the previous six months had a 45 percent lower risk of preeclampsia than non-users. The reduction in risk was more significant among lean women. When lean women were analyzed separately, those who used multivitamins had a 71 percent lower risk of preeclampsia than nonusers.

These results suggest that regular use of a multivitamin supplement in the months before and during pregnancy may help prevent preeclampsia, particularly among lean women.

Bodnar LM, et al. Periconceptional multivitamin use reduces the risk of preeclampsia. 2006. Am J Epidemiol 164(5):470-7.

Omega 3 Fatty Acids in Fish Oil Reduce Incidence of Age-related Macular Degeneration

2011-08-16T09:06:00.000-07:00

A recent study of a large population of women showed that regular consumption of fish and EPA and DHA (omega-3 fatty acids found in fish) was associated with a significant decrease in the risk of age-related macular degeneration, a major cause of blindness.

Age-related macular degeneration (AMD), a major cause of blindness, is estimated to affect 9 million U.S. adults. Evidence from observational and epidemiologic studies suggest an inverse relation between regular dietary intake of fish and DHA and EPA and the risk of advanced AMD.
In a recent study published online in the Archives of Ophthalmology, researchers examined whether the intake of omega-3 fatty acids and fish affects the incidence of AMD in women.

A detailed food-frequency questionnaire was completed by 38,022 women at an average age of 54.6 years. All women were free of a diagnosis of AMD at the beginning of the trial. After an average of 10 years follow-up, 235 cases of AMD were confirmed.

Women in the highest third of intake of DHA, compared to those in the lowest, had a 38% decreased risk of AMD. Those with the highest third of intake of EPA had a 34% decrease risk of AMD. Similarly to intakes of individual omega-3 fatty acids, women who consumed 1 or more servings of fish per week had a 42% decreased risk in comparison to those who ate less than 1 serving per month.

The results from this prospective study from a large population of women indicate that regular consumption of fish and omega-3 fatty acids from fish (EPA and DHA) significantly reduces the risk of AMD. This is some of the strongest evidence to date that support a role for long-chain fatty omega-3 fatty acids in the primary prevention of AMD, and possibly a reduction in the number of people who ultimately have advanced AMD, potentially leading to blindness.

William G. Christen, ScD et al. Dietary omega Fatty Acid and Fish Intake and Incident Age-Related Macular Degeneration in Women. Arch Ophthalmol. Published online March 14, 2011. doi:10.1001/archophthalmol.2011.34

Dietary Zinc Reduces Risk of Death From Prostate Cancer

2011-08-16T09:03:00.000-07:00

According to a new Swedish study, men with a higher intake of dietary zinc may reduce the risk of prostate-related death.

The mineral zinc is involved in numerous enzymes and many essential cellular functions, including health of the immune system and DNA repair. Although previous research supports a role for zinc in prostate carcinogenesis, epidemiologic data are currently inconsistent. Little to no data on cancer-specific survival and zinc intake has been reported.

In a recent study, researchers sought to determine whether dietary zinc, assessed near the time of prostate cancer diagnosis, is associated with an improvement in survival.

This population-based cohort consisted of 525 Swedish men less than 80 years of age with a diagnosis of prostate cancer made between 1989 and 1994. Study participants completed food-frequency questionnaires, and zinc intake was derived from nutrient databases. Deaths from prostate cancer as well as from all causes were documented through February 2009.

After an average follow-up of 6.4 years, 218 (42%) men died of prostate cancer and 257 (49%) died of other causes. Compared to the group with lowest zinc intakes, high dietary zinc intake was associated with a reduced risk of prostate cancer-specific mortality. The association was stronger in men with localized tumors. Zinc intake was not associated with mortality from other causes.

The results of this study suggest that high dietary intake of zinc is associated with lower prostate cancer-specific mortality after diagnosis, particularly in men with localized tumors.

Epstein MM, et al. Dietary zinc and prostate cancer survival in a Swedish cohort. 2011. Am J Clin Nutr 93(3):586-93.

Vegan Diets Short on Omega-3 and Vitamin B12 May Increase Cardiovascular Risk

2011-08-16T09:00:00.000-07:00

According to a new review, vegetarian and vegan diets may require additional omega-3 and vitamin B12 supplementation to reduce factors that increase heart disease risk.

A new review in the Journal of Agricultural and Food Chemistry indicates that many vegetarians, especially vegans, may unknowingly be at risk for certain cardiovascular health problems due to inadequate intakes of omega-3 fatty acids and vitamin B12.

The review stated that although meat eaters are known to have a significantly higher combination of cardiovascular risk factors than vegetarians, people following strict vegetarian and vegan diets are not invulnerable to risk. These diets tend to lack several key nutrients, including iron, zinc, vitamin B12, and omega-3 fatty acids.

Meat eaters are known to have a significantly higher incidence of certain cardiovascular risk factors compared with vegetarians, including increased BMI and waist-to-hip ratio, and higher blood pressure, plasma total cholesterol, and triglycerides. However, after reviewing 30 years of studies on vegetarianism, vegetarians and vegans typically have lower concentrations of serum vitamin B12 and omega-3 polyunsaturated fatty acid levels in tissue membrane phospholipids when compared to meat eaters.

Risks associated with low vitamin B12 and omega-3 status include an increase in blood clotting (platelet aggregation) due to increased levels of homocysteine, and decreased levels of ‘good’ HDL-cholesterol. Low HDL cholesterol and high homocysteine levels may be linked to an increase in cardiovascular and stroke risk.

The authors suggest that vegetarians, especially vegans, could benefit from increased dietary intake of omega-3 fatty acids to improve the balance and ratio of omega-3s to omega-6s. They can also benefit from increased vitamin B12 intake, including use of supplements containing vitamin B12 if necessary. Increasing dietary or supplemental omega-3 and vitamin B12 may reduce clotting tendencies that increase vegetarian and vegans’ otherwise low risk of cardiovascular disease.

Duo Li. Chemistry behind Vegetarianism. 2011. J Agric Food Chem 59(3):777–84.

During Pregnancy, Low–Glycemic Diets Improve Health Outcomes in Obese Women & Their Infants

2011-08-16T08:44:00.000-07:00

A new study shows that a low-glycemic load diet in overweight and obese pregnant women results in longer pregnancy duration, greater infant head circumference, and improved maternal cardiovascular risk factors.
Read more about this research below.

Excess body weight is known to complicate pregnancies, but the optimal diet during pregnancy is currently unknown. New research published in the American Journal of Clinical Nutrition aimed to examine the effects of a low–glycemic load (low-GL) diet in overweight and obese pregnant women.

Researchers randomly assigned 46 overweight or obese pregnant women to receive a low-GL or a low-fat diet. The women received carbohydrate-rich foods, fats, and snack foods through home delivery or study visits. Birth weight, infant body measurements, gestational duration, maternal weight gain, and maternal metabolic parameters were measured.

No significant differences in birth weight or measures of infant body fat were seen between the two groups. However, in the low-GL compared with the low-fat group, gestational duration was significantly longer and fewer deliveries occurred at less than 38.0 weeks (13% versus 48%). Adjusted head circumference was greater in the low-GL versus the low-fat group. Women in the low-GL group had smaller increases in triglycerides and total cholesterol and a greater decrease in C-reactive protein (a marker of inflammation).
In this study, a low-GL diet correlated with longer pregnancy duration, greater infant head circumference, and improved maternal cardiovascular risk factors. Researchers suggest that large-scale studies may be useful in determining whether a low-GL diet may be beneficial in the prevention of prematurity and other unfavorable maternal and infant outcomes.

Rhodes ET, et al. Effects of a low–glycemic load diet in overweight and obese pregnant women: a pilot randomized controlled trial. 2010. Am J Clin Nutr 92(6):1306-15.

Low Vitamin D Levels Linked to Prediabetes and Prehypertension

2011-06-19T19:35:00.000-07:00

A recently published study showed that adults with low vitamin D levels had more than double the risk of prehypertension and prediabetes than adults with higher vitamin D levels.

Prediabetes and prehypertension have been associated with low vitamin D levels. In a recent issue of the journal Diabetes Care, scientists report a correlation between reduced vitamin D levels and prediabetes and prehypertension in adults. Both prediabetes and prehypertension are estimated to exist in at least one-fourth of disease-free adults.

Researchers analyzed data from 898 men and 813 women who participated in the National Health and Nutrition Examination Survey (NHANES), 2001-2006. Blood pressure measurements were obtained during examinations conducted upon enrollment, and blood samples were evaluated for glucose, serum 25-hydroxyvitamin D and other factors.

Prediabetes was defined as having a fasting serum glucose of between 100 and 125 milligrams per deciliter, and prehypertension was defined as systolic blood pressure of 120 to 139 mmHg and/or diastolic blood pressure between 80 and 89 mmHg. Prediabetes was 33 percent higher among those with vitamin D levels of 76.3 nmol/l (30.5 ng/ml) or less compared to those with higher levels. Prehypertension was evident in 61 percent of those with the lower vitamin D levels. Participants with undiagnosed diabetes and untreated hypertension had even lower vitamin D levels on average. Serum vitamin D levels tended to decline with increasing age and body mass.

When the risk of having both conditions was considered, those with low vitamin D levels had 2.4 times the risk of that experienced by subjects with higher vitamin D levels.

It is reasonable that among those with prediabetes or prehypertension, vitamin D supplementation resulting in increased serum vitamin D levels may help reverse subtle changes in fasting serum glucose and resting blood pressure that may lead to more advanced disease states.

Alok K. Gupta, MD, Meghan M. Brashear, MPH and William D. Johnson, PHD. Prediabetes and Prehypertension in Healthy Adults Are Associated With Low Vitamin D Levels. Diabetes Care March 2011 vol. 34 no. 3 658-660.

Glycemic Load is a Better Predictor of Glycemic Response Than Carbohydrate Content Alone

2011-06-19T19:32:00.000-07:00

A new study provides evidence that the glycemic load of a meal is a better predictor of blood glucose and insulin response that simply accounting for total carbohydrates.

The glycemic load (GL) is a ranking system for carbohydrate content in food portions based on their glycemic index (GI) and the portion size. Glycemic load for a single serving of a food can be calculated as the quantity (in grams) of its carbohydrate content, multiplied by its GI, and divided by 100. While GL is increasingly used in nutritional research, its ability to predict postprandial (after meal) blood glucose and insulin response for a wide range of foods or mixed meals has been unclear.

In a recent issue of the American Journal of Clinical Nutrition, researchers sought to assess the degree of correlation between calculated GL and observed glucose and insulin responses in healthy subjects consuming calorically identical portions of single foods and mixed meals.

In study 1, healthy subjects consumed 240 calorie portions of 121 single foods in 10 food categories. In study 2, healthy subjects consumed 480 calorie servings of 13 mixed meals. Foods and meals varied widely in macronutrient content, fiber, and GL. Blood glucose and insulin responses were measured and compared to a reference food (= 100).

Among the single foods, GL was a more powerful predictor of postprandial glucose and insulin response than was the available carbohydrate content itself. Similarly, for mixed meals, GL was also the strongest predictor of postprandial glucose and insulin responses. Carbohydrate content alone was predictive of the glucose and insulin responses to single foods, but not to mixed meals.

The results of this study are the first to provide large-scale evidence of the superiority of using dietary GL over carbohydrate content alone to estimate postprandial glucose and insulin response in healthy individuals.

Jiansong Bao et al. Prediction of postprandial glycemia and insulinemia in lean, young, healthy adults: glycemic load compared with carbohydrate content alone. Am J Clin Nutr May 2011 vol. 93 no. 5 984-996.

Energy Expenditure is Reduced by Sleep Deprivation – A Possible Link to Obesity

2011-06-19T19:23:00.000-07:00

A new study shows that total sleep deprivation reduces energy expenditure and may partly explain the connection between poor sleep and an increased risk of obesity.

Observational and epidemiologic evidence has shown that chronic deficits in sleep are related to an increased risk of obesity, but the mechanisms behind this relation have not been fully explained.

In a recent study published in the American Journal of Clinical Nutrition researchers examined the effect of a single night of total sleep deprivation on food intake and morning energy expenditure.

Using a balanced crossover design, scientists examined 14 healthy, normal-weight males on 2 occasions during a regular 24 hour sleep-wake cycle (including 8 hours of nocturnal sleep) and a 24 hour period of continuous wakefulness. On the morning after regular sleep and total sleep deprivation, resting and postprandial (after meal) energy expenditures were analyzed. Food intake in both groups was assessed again in the late afternoon after the subjects were given a free-choice food intake from a large buffet. Circulating concentrations of ghrelin, leptin, norepinephrine, cortisol, thyreotropin, glucose, and insulin were repeatedly measured over the entire 24 hour session.

In comparison with normal sleep, resting energy expenditure was reduced by 5% and postprandial expenditure by 20% in the sleep deprived subjects. Nocturnal wakefulness increased morning plasma ghrelin concentrations (a hormone that stimulates hunger), and nocturnal and daytime circulating concentrations of thyreotropin, cortisol, and norepinephrine) as well as morning postprandial plasma glucose concentrations. Changes in food intakes were variable, and no differences between wake and sleep conditions were detected.

These research findings show that one night of sleep deprivation significantly reduces energy expenditure in the short-term, which suggests that sleep contributes to the regulation of daytime energy expenditure in humans.

Christian Benedict et al. Acute sleep deprivation reduces energy expenditure in healthy men Am J Clin Nutr June 2011 vol. 93 no. 6 1229-1236.

Magnesium Reduces Risk of Sudden Cardiac Death in Women

2011-04-08T17:08:00.000-07:00

A recent study involving a large group of women studied over 26 years found that those with the highest magnesium intake (and corresponding plasma levels) had a 41% lower risk of sudden cardiac death.

Magnesium has beneficial cardiovascular properties in cellular and experimental models, but its relation to sudden cardiac death (SCD) risk in humans is unclear.

In a recent study published in the American Journal of Clinical Nutrition, researchers examined the association between magnesium, as measured in diet and plasma, and risk of SCD. The association for magnesium intake was examined prospectively in 88,375 women who were free of disease in 1980 and part of the Nurses’ Health Study. Information on magnesium intake, other nutrients, and lifestyle factors was updated every 2–4 years through questionnaires. In this group of women, there were 505 cases of sudden or arrhythmic death documented over 26 years of follow-up.

After adjustment for confounders and potential intermediaries, the relative risk of SCD was significantly lower in women in the highest quartile of both dietary intake and plasma levels of magnesium (when compared to those in the lowest quartile). The inverse relation with SCD was stronger for plasma magnesium than dietary intake of magnesium, with each 0.25 mg/dL (one standard deviation) increment in plasma magnesium associated with a 41% lower risk of SCD.

In this study group of women, higher plasma concentrations and dietary intakes of magnesium were associated with lower risks of SCD. The researchers stated that if the observation is causal, interventions aimed at increasing dietary or plasma magnesium might lower the risk of sudden cardiac death.

Chiuve SE, et al. Plasma and dietary magnesium and risk of sudden cardiac death in women. 2011. Am J Clin Nutr 93(2):253-260.

Higher Dietary Fiber Intake Reduces Risk of Death in Older Adults

2011-04-08T17:04:00.000-07:00

In the largest diet and health study ever conducted, dietary fiber intake was associated with a reduced risk of overall death, including death caused specifically by cardiovascular, infectious, and respiratory diseases.

Previous research on dietary fiber has shown beneficial effects in lowering the risk of cardiovascular disease, diabetes, and some cancers. Less is known about the effect of dietary fiber on overall mortality and specific causes of death.

In a recent study published in the Archives of Internal Medicine, researchers analyzed dietary fiber intake in relation to total mortality and death from specific causes in the NIH (National Institutes of Health)-AARP Diet and Health Study. The study included over 500,000 men and women ages 50-71 who answered questionnaires with specific diet and lifestyle questions. Diet was assessed using a food-frequency questionnaire at baseline, then again after an average of 9 years of follow-up.

Researchers identified 20,126 deaths in men and 11,330 deaths in women during the study period. Cause of death was identified using the National Death Index Plus.

Dietary fiber intake was associated with a 22% reduction in risk of total death in both men and women. Dietary fiber intake also lowered the risk of death from cardiovascular, infectious, and respiratory diseases by 24% to 56% in men and by 34% to 59% in women. In men, there was an inverse association between dietary fiber intake and cancer death. Dietary fiber from grains was most closely related to a reduction in the risk of overall mortality and cause-specific death in both men and women.

Dietary fiber may reduce the risk of death from cardiovascular, infectious, and respiratory diseases. Ensuring adequate fiber intake by eating a fiber-rich diet appears to provide significant health benefits.

Park Y, Subar AF, Hollenbeck A, Schatzkin A. Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study. 2011. Arch Intern Med, published online 14-Feb-2011. doi:10.1001/archinternmed.2011.18 http://archinte.ama-assn.org/cgi/content/abstract/archinternmed.2011.18v1

Turmeric Extract

2011-03-26T15:37:00.000-07:00

Turmeric, a shrub related to ginger, is grown throughout India, other parts of Asia, and Africa. Known for its warm, bitter taste and golden color, turmeric is commonly used in fabric dyes and foods such as curry powders, mustard, and cheeses. It should not be confused with Javanese turmeric. Tumeric has several common names: turmeric, turmeric root, Indian saffron.

In traditional Chinese medicine and Ayurvedic medicine, turmeric has been used to aid digestion and liver function, relieve arthritis pain, and regulate menstruation. Turmeric has also been applied directly to the skin for eczema and wound healing. Today, turmeric is used for conditions such as heartburn, stomach ulcers, and gallstones. It is also used to reduce inflammation, as well as to prevent and treat cancer.

Turmeric's finger-like underground stems (rhizomes) are dried and taken by mouth as a powder or in capsules, teas, or liquid extracts. Turmeric can also be made into a paste and used on the skin.

Turmeric contains three major phytochemical compounds - called curcuminoids - which give turmeric its bright yellow-orange color (The most active component is curcumin.). These curcuminoids have been the focus of numerous clinical studies designed to investigate their long-term safety, antioxidant properties, and anti-inflammatory activity.

USANA put turmeric extract in several of its high end products, which includes Procosa II, OptOmega, and Hepasil DTX for the extra, secondary antioxidant protection. In OptOmega, it utilizes extra-virgin olive oil, tocopherols and tocotrienols, turmeric, and rosemary for superior antioxidant protection. The oils in OptOmega provide broad spectrum health benefits, including cardiovascular support, immune system support, and nutrients for healthy skin.

Tablet Over Liquid Vitamins

2011-03-26T13:15:00.000-07:00

Many liquid supplement manufacturers claim that because their product is in a liquid form it is more bioavailable. In fact, some even use phony statements regarding the Physician's Desk Reference to support such claims. The statement they reference about liquid supplements being more bioavailable first appeared in the PDR under a listing for a specific nutritional supplement product. That statement has since been removed because it could not be substantiated.

Nutrients are typically absorbed by the small intestine (unless they are taken sublingually or injected). When you ingest a supplement in either liquid or tablet form, it must first pass through the stomach before reaching the small intestine. If liquids were simply absorbed directly into the bloodstream, as some supplement companies claim, what would happen when individuals consumed soup? Would it also be absorbed directly into the bloodstream?

Bioavailability is defined as the degree and rate at which a substance (as a drug) is absorbed into a living system - or more correctly, the degree or rate at which it is ultimately made available at the site of physiological activity. Different vitamins and minerals have different absorption rates regardless of whether they come from a tablet, liquid, powder, or food. Calcium, for example, has a fairly standard absorption rate (25-35%), and the form does not generally make a significant difference.

A well-made tablet provides a very effective delivery system and is the chosen form of most pharmaceutical medications. This is because tablets have been confirmed, through years of carefully controlled studies, as a reliable and efficient delivery system for medications. Why would vitamin and mineral supplements be any different? Does anyone doubt that an aspirin tablet is ineffective because it comes in a tablet?

Tableted products can also provide an increased amount of active ingredient (almost 3x as much as a capsule and much more than a liquid or spray). In general, the stability of tablets is also superior to liquids.

Bioavailability is a complicated topic because it is not dependent solely on product formulation. Many external factors can affect the absorption of vitamins, minerals, and other compounds. Some of these factors are a function of the person taking the nutrient, including age, digestive system integrity, overall health status, the time of day, gender, and if the product is taken on a full or empty stomach. People whose nutrient needs are greater - such as growing children, pregnant or lactating women, and those who are currently deficient - may have significantly enhanced absorption rates for certain nutrients.

Recently, some individuals and companies have made claims that their products are superior because they are "98% absorbed" or some similar number. This is a misleading statement because there are far too many variables to imply that an individual's absorption is a certain percent of the material consumed. Even absorption of minerals from food sources can vary significantly. Boron, molybdenum, and iodine can be absorbed at over 90 percent, while the average absorption rates of zinc, copper, and selenium range from 30 to 80 percent depending on the form. As such, stating an absolute absorption rate on product packaging or advertising is almost always misleading.

USANA tablets are formulated to meet United States Pharmacopoeia standards, which require full disintegration within 30-45 min. They are also formulated to meet standards for dissolution. Innovative formulations have been developed to optimize nutrient bioavailability. Each lot of USANA tablets is tested against finished product specifications to ensure that standards are met for identity, target weight, hardness, thickness, disintegration, potency, purity, and microbial counts.

The dietary supplement industry could not exist without rigorous, peer-reviewed studies that used tableted forms of vitamins and minerals to establish what we is now regarded as common nutritional knowledge. With thousands of studies connecting various vitamins and mineral supplements with markers of health, it is impossible to dispute the effectiveness of tablets as a delivery system. If tablets were ineffective, why have so many researchers observed positive results? If liquid or spray supplements are obviously superior, why are they rarely - if ever - used in published scientific research?

(Keep in mind that this article primarily addresses multivitamin formulations. There may be certain products, such as children's medicines, that are more appropriate in liquid form. However, such products are the exception - not the rule.)

Finally, liquid supplement promoters often contend that liquids are better because they don't contain fillers (excipients used in tablets for disintegration, form, binding, coating, etc). This is perhaps the most illogical argument of all, since liquid supplements require many more "other" ingredients, including emulsifiers, solvents, preservatives, stabilizing agents, coloring, flavoring, and more. Generally speaking, the more vitamin and mineral ingredients there are in a liquid supplement, the more excipients that product will require.

Higher Level of Vitamin D Necessary

2011-03-26T13:09:00.000-07:00

Vitamin D is a fat-soluble vitamin that is naturally present in very few foods, added to others, and available as a dietary supplement. It is also produced endogenously when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D obtained from sun exposure, food, and supplements is biologically inert and must undergo two hydroxylations in the body for activation. The first occurs in the liver and converts vitamin D to 25-hydroxyvitamin D [25(OH)D], also known as calcidiol. The second occurs primarily in the kidney and forms the physiologically active 1,25-dihydroxyvitamin D [1,25(OH)2D], also known as calcitriol.

Vitamin D is essential for promoting calcium absorption in the gut and maintaining adequate serum calcium and phosphate concentrations to enable normal mineralization of bone and prevent hypocalcemic tetany. It is also needed for bone growth and bone remodeling by osteoblasts and osteoclast. Without sufficient vitamin D, bones can become thin, brittle, or misshapen. Vitamin D sufficiency prevents rickets in children and osteomalacia in adults. Together with calcium, vitamin D also helps protect older adults from osteoporosis.

Vitamin D has other roles in human health, including modulation of neuromuscular and immune function and reduction of inflammation. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. Many laboratory-cultured human cells have vitamin D receptors and some convert 25(OH)D to 1,25(OH)2D. It remains to be determined whether cells with vitamin D receptors in the intact human carry out this conversion.

Vitamin D deficiency is now recognized as a worldwide problem. Poor dietary intake and lack of moderate sun exposure have resulted in widespread vitamin D deficiencies throughout much of the world. Additionally, very few foods contain vitamin D naturally, and foods fortified with vitamin D are typically inadequate to satisfy adult vitamin D requirements.

Numerous recent scientific research papers and our own in-house clinical research suggests that higher vitamin D levels - much higher than previously thought - are needed for most people to attain optimal blood levels of vitamin D. USANA's recent change to the Mega AO formulation is a reflection of this recent research and an ongoing commitment to provide USANA customers with the most effective, scientifically valid, and up-to-date products possible.

Why Usana Uses Soy

2011-03-26T12:27:00.000-07:00

USANA uses soy as a major source of protein in its bars and drink mixes. A variety of factors have gone into this decision. The most important involve the fact that soy protein is nutritionally complete and high quality, and soy consumption has been linked with several long-term health benefits. In addition, soy protein is ecologically friendly. Its production has a much lotheyr environmental impact than does the production of most animal protein foods.

This does not mean they don’t appreciate the nutritional value of other proteins. Whey protein, for example, is also high quality from a nutritional perspective, and may have some advantages for those whose primary goal is to build muscle. It also has some advantages in taste and mouthfeel, although netheyr soy isolates are catching up in the sensory arena. They also recognize the value of rice, pea, and other protein concentrates, but note that few of these are as complete or balanced as soy and whey.

In general, though, our position is that a healthy diet includes protein from a wide variety of sources - including whole foods (legumes, whole grains, meat, dairy, and fish) as well as healthy processed foods. In this context, they believe that soy, whey, and other protein isolates and concentrates can play a role as components of healthy, well-balanced diets.

That said, they are also aware that the world of protein isolates and concentrates is filled with controversy. Much of what they see on the Internet and in certain popular magazines is strongly pro-whey and anti-soy, or strongly pro-soy or anti-whey, as if one or the other of these protein sources were “all good” or “all bad” for all people in all situations. In most instances, such stories are associated (either overtly or covertly) with food marketing campaigns. They are part of the “sticks and stones” that get thrown back and forth bettheyen the soy, whey, and meat factions who compete for your food dollars.

Is there any truth in what they are saying? Many times there is, but too often those truths are “half truths” or “facts spun out of context” with the intent of swaying purchasing behavior.

Is soy the preferred protein source for everyone? No. Clearly there are people who are sensitive or allergic to soy, and these individuals should avoid or limit their intakes of soy protein. Similarly, there are people who are allergic to dairy and who should avoid whey protein. People who are vegetarian or vegan may want to avoid whey protein because it is animal-based.

But to USANA scientists, these are not sufficient grounds for making the choice bettheyen whey and soy proteins an all-or-nothing, black-and-white proposition for the vast majority of people.

The industrial-grade bickering that has characterized much of the soy versus whey debate has left many consumers confused, concerned, and generally hungry for objective information on what they should eat. The purpose of this position paper is to summarize in an objective way our interpretation of what nutritional science has to say about several key issues that lie at the heart of arguments for and against soy protein.

In conclusion, USANA believes that soy is a healthy source of protein for the vast majority of people. Clearly there are people who are allergic and/or sensitive to soy, and those people need to limit their soy intakes or avoid soy all together. But the scientific research they have seen indicates that this group is relatively small.

That said, each of us is the best judge of what foods they should be eating. If you experience side effects from eating soy foods (even if you don’t have a diagnosed soy allergy), it makes full sense for you to minimize or eliminate sources of soy intake.

They encourage everyone to become an active “student” of nutrition - to seek out objective information from a variety of sources concerning the foods they eat. They encourage everyone to question information that doesn’t make common sense or that sounds too good or too scary to be true.

As always, the most solid, common sense advice they can provide concerning your protein sources is: a healthy diet is one that includes protein from a wide variety of sources, including whole foods (legumes, whole grains, meat, dairy, and fish) and healthy processed foods. In this context, they believe that soy, whey, and other protein isolates and concentrates can all play a role as components of healthy, balanced diets.

References:
The Nutritional Value of Soy Protein
Soy Allergies and Sensitivities
Soy and Weight Loss

Pregnancy Complications may be Related to Low Vitamin D Levels

2011-03-26T12:11:00.000-07:00

Early-onset severe preeclampsia occurs in roughly 2 to 3 percent of pregnancies, and it contributes to about 15 percent of preterm births in the U.S. each year. New research shows that pregnant women with low vitamin D levels are at higher risk for this condition.

Studies have linked low vitamin D levels to an increased risk of many diseases, including type 1 diabetes, asthma, heart disease, certain cancers and depression. A new study has found that women who develop a severe form of pregnancy-related high blood pressure tend to have lower blood levels of vitamin D than healthy pregnant women.

Preeclampsia is a syndrome marked by a sudden increase in blood pressure and kidney dysfunction. Early-onset severe preeclampsia is a particularly serious form that arises before the 34th week of pregnancy.

In a recent study, researchers compared vitamin D levels in 50 women with early severe preeclampsia to vitamin D levels of 100 healthy pregnant women. The average vitamin D level in the preeclampsia group was 18 ng/mL compared to an average of 32 ng/mL in the healthy group. A 10 ng/mL increase in vitamin D levels was linked to a 63 percent reduction in risk of the complication.

Since total Vitamin D levels in the blood seem to be linked to an increase in this pregnancy complication, further study is needed to understand the impact of vitamin D deficiency on pregnancy outcomes.

Robinson CJ, Alanis MC, Wagner CL, et al. Plasma 25-hydroxyvitamin D levels in early-onset severe preeclampsia. 2010. Am J Obstet Gynecol 203:ePub ahead of print.

Poor Magnesium Status May Be Related to Metabolic Syndrome

2011-03-26T12:09:00.000-07:00

In a recent study, lower Magnesium levels correlated with an increased number of metabolic syndrome risk factors.

Metabolic syndrome has been defined as the presence of abdominal obesity combined with two of the following factors: hypertension, dyslipidemia, impaired glucose tolerance, or diabetes mellitus. Magnesium is an essential cofactor for more than 300 enzymes involved in carbohydrate and lipid metabolism.

In a recent study, researchers enrolled 117 overweight and obese patients and measured serum magnesium levels together with fasting serum glucose, high-density lipoprotein cholesterol (HDL), and triacylglycerols. Researchers found a strong inverse relationship between serum magnesium levels and the presence of metabolic syndrome. In addition, as the level of serum magnesium decreased, the number of factors relating to metabolic syndrome increased. Also, there was an inverse relationship between serum magnesium levels and high-sensitivity C-reactive protein (a marker of inflammation).

The scientists concluded that decreased levels of serum magnesium are associated with increased risk for metabolic syndrome, possibly due to a low-grade inflammatory process.

Angelos A, et al. An inverse relationship between cumulative components of the metabolic syndrome and serum magnesium levels. 2008. Nutrition Research 28(10):659-63.

Vitamin D3 May Reduce the Risk of Colorectal Cancer

2011-03-26T12:03:00.000-07:00

According to a new research study published in the American Journal of Epidemiology, increased blood levels of vitamin D may reduce the risk of colorectal cancer by up to 40 percent.

In a new study, researchers examined the association between circulating 25-hydroxyvitamin D(3), the best indicator of total vitamin D exposure, and incident, sporadic colorectal cancer risk. Data was obtained from a pooled analysis of three colonoscopy-based case-control studies conducted in Minnesota, North Carolina, and South Carolina between 1991 and 2002. In total, 616 people individuals with colorectal cancer were compared to 770 polyp-free control subjects.

Analysis showed that higher circulating vitamin D3 concentrations were associated with a decrease in colorectal cancer risk of 40%. In participants that were also using NSAIDs (anti-inflammatory medications), the potential risk reduction of higher vitamin D levels increased to 66%.

These findings support the idea that higher vitamin D levels may reduce the risk of colorectal cancer, especially when combined with anti-inflammatory agents. The human body manufactures vitamin D upon exposure to sunshine, but in some northern regions sunlight levels during the winter are inadequate for synthesizing vitamin D. Therefore, dietary supplements and fortified foods are generally an efficient way to boost circulating levels of vitamin D.

Fedirko RM, et al. Blood 25-Hydroxyvitamin D3 Concentrations and Incident Sporadic Colorectal Adenoma Risk: A Pooled Case-Control Study V. 2010. American Journal of Epidemiology

Increased Magnesium Intake Linked to Lower Risk of Type 2 Diabetes

2011-03-26T11:55:00.000-07:00

Type 2 diabetes prevalence is rising in Asian countries. New research indicates that increased magnesium intake may reduce the risk of type 2 diabetes in Japanese adults.

A new study published in the Journal of the American College of Nutrition reports a correlation between higher magnesium intake and a reduced rate of type 2 diabetes. Low magnesium intakes have previously been linked to insulin resistance and impaired glucose utilization.

Researchers evaluated data from 17,592 men and women aged 40 to 79 who took part in the Japan Collaborative Cohort Study for Evaluation of Cancer Risk established between 1988 and 1990. Dietary magnesium was calculated using a validated questionnaire, and incidence of diabetes was defined by self-report of physician diagnosis.

At the five year follow-up, 459 new cases of diabetes were reported. Dietary intake of magnesium was inversely associated with age, body mass index (BMI), and diabetes incidence in both sexes.

After making adjustments for cardiovascular risk factors, participants whose intake of magnesium was among the top 25 percent had a 36 percent lower adjusted risk of developing diabetes.

The incidence of type 2 diabetes is increasing in Asian countries, and this is the first study to examine the association between magnesium intake and the risk of diabetes in adults living in Japan. The results of this study are important for the development of potential health policies to help prevent and control this increasingly common degenerative disease.

Kyoko K, et al. Magnesium Intake and Risk of Self-Reported Type 2 Diabetes among Japanese. 2010. Journal of the American College of Nutrition, Vol. 29, No. 2, 99-106.

High Fiber Intake Reduces Risk of Heart Disease

2011-03-26T11:45:00.000-07:00

High dietary fiber intake, especially from a variety of sources, is related to a reduction in many cardiovascular disease risk factors.

Increased dietary fiber intake is associated with reduced risk of cardiovascular disease. The results of a study published in the December 2005 issue of the American Journal of Clinical Nutrition added unique insight to the growing body of evidence linking higher dietary fiber intake with reduced risk of heart disease.

Data was collected from roughly 2,500 men and 3,500 women (5,961 total). These individuals were already participating in the SU.VI.MAX Study, a trial designed to evaluate the effect of antioxidants on cancer and heart disease incidence over an eight year period. Participants from this study were selected because the SU.VI.MAX Study already required detailed dietary information, making it easy to estimate fiber intakes for the participants.

Higher total and insoluble dietary fiber intakes were associated with reductions in the risks of elevated waist-to-hip ratio (a marker of obesity), hypertension (high blood pressure), plasma apolipoprotein B (LDL cholesterol), apolipoprotein B to apolipoprotein A-I ratio (LDL to HDL ratio), triacylglycerols, and homocysteine. Fiber from cereals was associated with a lower body mass index (BMI), blood pressure, and homocysteine concentration; fiber from vegetables with a lower blood pressure and homocysteine concentration; and fiber from fruit with a lower waist-to-hip ratio and blood pressure. Fiber from dried fruit or nuts and seeds was associated with a lower body mass index, waist-to-hip ratio, and fasting apo B and glucose concentrations.

The findings of this study illustrate the significance of increasing fiber intake from various dietary sources. The results also indicate that 25 grams total dietary fiber per day may be the minimum intake required to attain a significant protective effect against cardiovascular disease, and that total dietary fiber intakes of 30-35 grams/day might provide an even greater protective effect.

Lairon D, Arnault N, Bertrais S, Planells R, Clero E, Hercberg S, Boutron-Ruault MC. Dietary fiber intake and risk factors for cardiovascular disease in French adults. 2005. AJCN 82(6):1185-94.

USANA Nutritionals Pharmaceutical Grade

2011-03-26T11:41:00.000-07:00

Pharmaceuticals must meet certain standards for quality as established by the United States Pharmacopeia (or USP). The USP is a non-profit organization that works closely with the Food and Drug Administration (FDA), the pharmaceutical industry, and health care professionals to establish authoritative standards. These standards are enforceable by the FDA and the governments of more than 35 other countries, and are recognized worldwide as the hallmark of pharmaceutical manufacturing quality.

As you may have noticed, the following statement appears on many USANA product labels:

"Laboratory tested, quality guaranteed. Meets USP specifications for potency, uniformity, and disintegration where applicable."

USANA voluntarily adheres to a rigorous quality assurance program modeled after the pharmaceutical industry. This high standard of manufacturing separates USANA from many other dietary supplement companies.

USANA occasionally receive inquiries asking whether the FDA has audited USANA's facilities for Pharmaceutical GMP compliance. Unfortunately, the answer to this question is no. Because the FDA uses the Dietary Supplement Health and Education Act (DSHEA) as its legal guideline, our products - regardless of advanced voluntary quality control measures - can only be audited according to DSHEA rules, which currently require adherence to Dietary Supplement GMPs only.

However, please note that USANA products are considered over-the-counter drugs in Canada and Australia, and USANA continues to be audited to drug GMP equivalents by the regulatory organizations in these countries.

Omega–3 Fatty Acid Intake & The Incidence of Age-related Macular Degeneration

2011-03-26T11:25:00.000-07:00

Results recently published from a long-term study indicate that people at risk for age-related macular degeneration (AMD) may significantly reduce the risk of this disease by increasing their dietary intake of omega-3 fatty acids from oily fish, nuts and seeds, and fish oil supplements.

Omega-3 fatty acids are important for the vascular and neural health of the retina and may influence the risk of developing age-related macular degeneration (AMD). There are two forms of AMD: dry and wet. In the dry form, normal tissue in the macula slowly disappears, leaving a pale area referred to as central geographic atrophy (CGA). In the wet form, or neovascular (NV) AMD, abnormal blood vessels grow underneath the macula. These vessels leak serum or blood and eventually cause the normal macular tissue to be replaced by scar tissue.

Researchers recently investigated whether omega-3 fatty acid intake was associated with a reduced risk of developing both wet and dry forms of AMD. The study involved 1837 people from the Age-Related Eye Diseases Study (AREDS) who were at moderate to high risk of developing AMD. Clinical measurements were obtained in this group over a period of 12 years (from 1992 to 2005).

Participants who reported the highest omega–3 fatty acid intake were 35% less likely than their peers to develop dry (CGA) AMD, and 32% less likely to develop the more common, wet form (NV) AMD.

Over the 12 years of this study, the incidence of CGA and NV AMD was lowest for those reporting the highest consumption of omega-3 fatty acids, which are found primarily in oily fish, nuts and seeds, and fish oil supplements. If these results are applied to the general population, dietary intervention may have a significant preventive effect on the development and progression of AMD.

Am J Clin Nutr. 2009 Dec;90(6):1601-7

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Essential Fatty Acids for Eye Healt

Quercetin Reduces Blood Pressure in Adults with Hypertension

2011-03-26T11:22:00.000-07:00

Quercetin, an antioxidant found in onions, berries, and apples, is associated with a reduced risk of heart disease and stroke. Supplementation with quercetin has been shown to reduce hypertension in animal models, but until now has never been tested in hypertensive humans.

Researchers at the University of Utah, in collaboration with USANA Health Sciences, conducted a randomized, double-blind, placebo-controlled, crossover study to test the effectiveness of quercetin supplementation in lowering unhealthy blood pressure levels. The subjects were divided into two groups: prehypertensives (120-139 mm Hg systolic/80-89 mm Hg diastolic) or stage 1 hypertensives (140-159 mm Hg systolic/90-99 mm Hg diastolic). Over 28 days, the participants were given either 730 mg quercetin/day or placebo.

Blood pressure remained unchanged in prehypertensives after supplementation with quercetin. In contrast, stage 1 hypertensive subjects showed significant reductions in both systolic (-7 mm Hg) and diastolic (-2 mm Hg) blood pressure after quercetin supplementation. This is the first published study to show that quercetin supplementation can reduce blood pressure in hypertensive adult humans. Additionally, it is important to note that quercetin supplementation did not influence the blood pressure of non-hypertensive individuals.

J. Nutr. 137:2405-2411, November 2007

Vitamin D Levels Linked to Healthy Lung Function

2011-03-26T11:19:00.000-07:00

Vitamin D may play a role in keeping our lungs healthy, with higher concentrations of vitamin D resulting in positive effects on lung function and health.

Low concentrations of vitamin D have been associated with a number of diseases. Research out of New Zealand indicates that serum concentrations of vitamin D may also influence pulmonary (lung) function.

In a study published in the journal Chest, original analysis was performed on data from 14,091 adult subjects (all participants in the U.S. National Health and Nutrition Examination Survey conducted between 1988 and 1994). Lung function was measured in two ways: by the volume of air that could be forcibly blown out in total (forced vital capacity, or FVC), and the volume blown out in one second (forced expiratory volume, or FEV1). Vitamin D was measured using serum 25-hydroxyvitamin D, a standard indicator of vitamin D levels.

After adjusting for age, gender, height, body mass index, ethnicity, and smoking history, the difference in lung function between the groups with the highest and lowest vitamin D intake was substantial in both the FVC and FEV1 tests (172 mL and 126 mL respectively, p <0.0001). Further adjustment for physical activity, vitamin D supplementation, milk intake, and serum antioxidant status revealed additional strong correlation between the highest and lowest intake groups (142 mL (FVC) and 106 mL (FEV1), p < 0.0001).

Although further studies are necessary to determine whether vitamin D supplementation may be beneficial in cases of chronic respiratory disease, this study has shown that vitamin D may have a positive influence on pulmonary health, with greater levels of vitamin D associated with more positive benefits.

Chest 2005 Dec;128(6):3792-8

Vitamin D Deficiency Associated with Cardiovascular Disease Prevalence

2011-03-26T11:13:00.000-07:00

In a large sample of U.S. adults, new research indicates that vitamin D deficiency is associated with an increased prevalence of cardiovascular disease.

Inadequate vitamin D levels are known to be associated with certain cardiovascular disease (CVD) risk factors, but until recently the association between vitamin D levels and the prevalence of CVD had not been comprehensively examined in the general U.S. population.

In a recent study published in Atherosclerosis, researchers examined data from the Third National Health and Nutrition Examination Survey (NHANES), a population-based sample of more than 16,000 U.S. adults.

In the total survey population, 1,308 subjects had some form of CVD. Using the standard definition of vitamin D deficiency (a serum level below 20 ng/mL), participants with CVD had a higher incidence of vitamin D deficiency (29.3%) than those without CVD (21.4%). After adjusting for age, gender, race/ethnicity, season of measurement, physical activity, body mass index, smoking status, hypertension, diabetes, elevated cholesterol, chronic kidney disease, and vitamin D use, the researchers showed that subjects deficient in vitamin D had a 20% increased risk of CVD.

The results of this analysis indicate a significant relationship between vitamin D deficiency and CVD prevalence in a large, highly representative sample of the U.S. adult population.

Atherosclerosis 2009 Jul; 205(1):255-60.

What USANA Products for Pregnant or Breast-feeding Women?

2011-03-26T10:49:00.000-07:00

The Essentials can serve as an excellent prenatal multivitamin. Proper amounts of folic acid, zinc, and other important vitamins and minerals are all present in this product.

It is important for women who are planning to become pregnant (and those who are currently pregnant) to consume at least 400 mcg of folic acid per day. A full daily dosage of the Essentials provides 1,000 mcg of folic acid. If a mother does not have adequate intake of folic acid within the first few months of pregnancy, the fetus may develop neural tube defects (such as spina bifida). Studies show that taking at least 400 mcg of folic acid can reduce the risk of these birth defects by as much as 70%.

It is important for every expectant mother to ask a doctor about taking an iron supplement, as iron is not included in the Essentials. During pregnancy, women should generally supplement with somewhere between 28 and 90 mg of elemental iron per day, depending on their needs.

Research has also shown that essential fatty acids are critical for developing babies. It may be a good idea to supplement with BiOmega during pregnancy. Before taking any additional or different supplements, discuss them fully with your doctor, as it is important to protect the growing baby and mother.

READ VERY CAREFULLY - The following products, taken as directed, are strongly recommended for women who are pregnant or lactating:

* Essentials
* Active Calcium
* BiOmega

The following products, taken as directed, are generally recommended for women who are pregnant or lactating, based on individual needs:

* USANA Foods (Nutrimeal, Nutrition Bar, Fibergy)

The following products, taken as directed, are recommended for women who are pregnant or lactating ONLY on the advice of a physician:

* HealthPak
* Proflavanol & Proflavanol 90
* E-Prime
* Poly C
* Ginkgo-PS
* Visionex

The following products are NOT generally for use by pregnant or lactating women:

* CoQuinone 30
* Hepasil DTX
* Procosa II
* PhytoEstrin
* Palmetto Plus

Body Mass Index Associated with Risk of All-cause Mortality

2011-02-22T09:52:00.000-08:00

In white adults, being overweight or obese (and possibly underweight) is associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

A high body-mass index (BMI) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain.

A large analysis reported in the December 2, 2010 issue of the New England Journal of Medicine confirms the relationship between being overweight or obese and a greater risk of dying from all causes.

An international team of researchers pooled data from 19 prospective studies totaling 1,462,958 white male and female participants between the ages of 19 and 84. Body mass index (BMI), calculated by dividing a person’s weight in kilograms by the square of their height in meters, was determined for all subjects. The participants were followed for periods that ranged from a maximum of 7 to 28 years, during which 160,087 deaths occurred.

Upon enrollment, the average BMI was 26.2. Compared with women whose body mass index was between 22.5 and 24.9, having a BMI of 25 to 29.9 was associated with a 13 percent greater risk of death over the period of follow-up. This risk rose with increasing body mass index categories, with women whose BMI was 40 to 49.9 having 2.5 times the risk of death from all causes than those with a BMI of 22.5 to 24.9. Risks among men were similar. Although a small risk of death was also observed for those whose BMI was below 20, the authors suggest that the finding was in part caused by preexisting disease.

In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

de Gonzalez AB, Phil D, et al. Body-Mass Index and Mortality among 1.46 Million White Adults. 2010. N Engl J Med 363:2211-9.

To learn more and calculate your BMI, see the following link: http://www.nhlbisupport.com/bmi

Supplemental Vitamins During Breast Cancer Treatment May Reduce Mortality Risk

2011-02-22T09:47:00.000-08:00

In a large population-based study of Chinese women with breast cancer, multivitamin use reduced the risk of mortality and the risk of cancer recurrence.

Nutritional supplement use during cancer treatment is currently controversial. Antioxidants may protect normal cells from oxidative damage that occurs during radiotherapy and certain chemotherapy regimens. However, the same mechanism could protect tumor cells and potentially reduce effectiveness of some cancer treatments. Recently, researchers evaluated vitamin supplement use during cancer treatment and in the first six months after breast cancer diagnosis, looking for correlations with total mortality and cancer recurrence.

A population-based prospective cohort study of 4,877 women diagnosed with invasive breast cancer was conducted between March of 2002 and April of 2006 in Shanghai, China. The women (aged 20-75) were interviewed approximately six months after diagnosis, then followed-up with later via in-person interviews.

During an average follow-up of 4.1 years, 444 deaths and 532 recurrences occurred. Vitamin use shortly after breast cancer diagnosis was associated with reduced risk of mortality and recurrence. Women who used nutritional supplements (vitamin E, vitamin C, multivitamins) had an 18% reduction in risk of mortality and a 22% reduced recurrence risk. The inverse association was found regardless of whether vitamin use was concurrent or non-concurrent with chemotherapy, but was only present among patients who did not receive radiotherapy.

Vitamin supplement use in the first six months after breast cancer diagnosis may be associated with reduced risk of mortality and recurrence. The results of this study do not support the current recommendation that all breast cancer patients should avoid use of vitamin supplements.

Nechuta S, et al. Vitamin supplement use during breast cancer treatment and survival: a prospective cohort study. Cancer Epidemiol Biomarkers Prev, 21 Dec 2010.

Healthy Eating Patterns Increase Survival Rates in Older Adults

2011-02-15T20:27:00.000-08:00

A newly published study supports the idea that a relatively low-fat, plant-based diet increases quality of life and survival in older adults.

A report published in the January 2011 issue of the Journal of the American Dietetic Association concluded that eating healthy food really does increase survival in older adults.

Researchers analyzed data from 2,582 participants in The Health, Aging and Body Composition Study. Participants were American adults aged 70 to 79 upon enrollment. Dietary questionnaires completed during the second year after enrollment were used to identify 6 predominant dietary patterns: high-fat dairy products, meat, fried foods and alcohol, breakfast cereal, refined grains, sweets and desserts, and healthy foods. The healthy foods diet was characterized by a higher intake of low-fat dairy products, fruit, whole grains, poultry, fish and vegetables, and reduced consumption of meat, fried foods, sweets, high-calorie drinks and added fat.

During the follow-up period of up to 10 years, 739 deaths occurred in the study group. Those whose diets consisted of healthy food had a significantly lower risk of dying than those whose diets were dominated by high-fat dairy products (ice cream, cheese, whole milk), meat, fried foods and alcohol, sweets, and other desserts. Researchers found a 40 percent greater risk of dying among those who consumed relatively higher amounts of high-fat dairy products, and a 37 percent greater risk for those whose diets were characterized by a lot of sweets.

This study's findings are consistent with current guidelines to consume relatively high amounts of vegetables, fruit, whole grains, poultry, fish, and low-fat dairy products. Diets that follow this pattern appear to be associated with superior nutritional status, improved quality of life, and higher rates of survival in older adults.

Anderson AL, et al. Dietary Patterns and Survival of Older Adults. 2011. Journal of the American Dietetic Association 11(1):84-91.

Multivitamin Supplementation May Have Positive Effects on Body Weight

2011-02-12T08:06:00.000-08:00

New research suggests that obese individuals who use a multivitamin and mineral supplement may experience both a decrease in body weight and improved serum lipid profiles.

Obese individuals are more likely to have lower blood concentrations of most vitamins and minerals. Unfortunately, there is currently limited information on the effects of nutritional supplementation on body weight control and energy metabolism in obese adults.

In new research published in the International Journal of Obesity, scientists evaluated the effects of multivitamin/mineral supplementation on body fat, energy expenditure, and lipid profiles in obese Chinese women.

Ninety-six obese Chinese women between the ages of 18 and 55 participated in a 26-week randomized, double-blind, placebo-controlled intervention study. Subjects were divided into three groups, receiving either a multivitamin/mineral supplement (MMS), 162mg of calcium, or placebo daily. Body weight, BMI, waist circumference, fat mass, lean tissue, resting energy expenditure, blood pressure, fasting plasma glucose and serum insulin, total cholesterol, LDL and HDL cholesterol, and triglycerides were measured at the beginning and end of the study period.

After 26 weeks, the multivitamin/mineral group had significantly lower body weight, BMI, fat mass, total and LDL cholesterol, significantly higher resting energy expenditure and HDL cholesterol than individuals in the placebo group. They were also more likely to have a reduced waist circumference. The calcium group also had significantly higher HDL cholesterol and lower LDL cholesterol levels compared with the placebo group.

The results suggest that multivitamin/mineral supplementation could reduce body weight and fatness and improve serum lipid profiles in obese women, possibly through increased energy expenditure and fat oxidation.

Li Y, Wang C, Zhu K, Feng RN, and Sun CH. Effects of multivitamin and mineral supplementation on adiposity, energy expenditure and lipid profiles in obese Chinese women. 2010. Int J Obes (Lond) 34(6):1070-7.

Compound From Olive Fruit Shows Heart Health Potential

2011-01-24T18:03:00.000-08:00

New research shows portion-controlled meal replacement diets as more effective than standard diets at both initial weight loss and long-term weight maintenance in type 2 diabetics.
In a recent study, supplementing with hydroxytyrosol – a polyphenolic compound extracted from olives – correlated with higher activity levels of the enzyme arylesterase, an antioxidant biomarker, and lower levels of oxidized LDL cholesterol. Oxidized LDL is believed to be a major player in promoting atherosclerosis (the build-up of fatty plaques in arteries) and general cardiovascular disease.

Hydroxytyrosol is thought to be the main antioxidant compound in olive fruit, and it is believed to play a significant role in many of the health benefits attributed to olive oil. Previous research has linked the compound to cardiovascular benefits, typically reductions in LDL or “bad” cholesterol. Data has also suggested the compound may boost eye health and reduce the risk of macular degeneration.

Spanish researchers reported these most recent results in the British Journal of Nutrition. Twenty-two healthy volunteers between 20 and 45 years of age and with a BMI between 18 and 33 kg/m2 were recruited. Volunteers were randomly assigned to receive 10 to 15 grams per day of hydroxytyrosol-enriched sunflower oil or non-enriched sunflower oil for three weeks. The former provided a daily hydroxytyrosol dose of between 45 and 50 mg. After the initial three week period, volunteers had two weeks of no intervention before crossing over to receive the other intervention.

Results showed no changes in total, LDL, or HDL-cholesterol between the groups. However, consumption of the hydroxytyrosol-enriched sunflower oil produced significant reductions in oxidized LDL from 79.8 units per liter at the start of the study to 64.1 U/l after three weeks, compared to an increase from 72.7 to 86.4 U/l during the control phase. Furthermore, the activity of arylesterase increased from 235.2 to 448.9 U/l during the hydroxytyrosol phase, compared with an increase from 204.1 to 310.3 U/l during the control phase.

The researchers reported that although hydroxytyrosol-enriched sunflower oil did not significantly reduce LDL-cholesterol or increase HDL-cholesterol, it acted as a functional food by increasing arylesterase activity and reducing oxidized LDL. Based on these results, dietary sources of hydroxytyrosol appear to be capable of reducing certain risk factors associated with coronary artery disease.

Vazquez-Velasco M, et al. Effects of hydroxytyrosol-enriched sunflower oil consumption on CVD risk factors. 2010. Br J Nutr, ePub ahead of print. doi: 10.1017/S0007114510005015

Meal Replacements Better Than Standard Diets for Weight Loss in Diabetics

2011-01-24T17:35:00.000-08:00

New research shows portion-controlled meal replacement diets as more effective than standard diets at both initial weight loss and long-term weight maintenance in type 2 diabetics.

A recent study published in Diabetes Education compared the efficacy of a portion-controlled meal replacement diet (PCD) to a standard diet (SD) based on American Diabetes Association recommendations in achieving and maintaining weight loss.

Participants included 119 overweight men and women with type 2 diabetes and a body mass index (BMI) between 25 and 40. Subjects were randomly assigned to one of two diets (PCD or SD) that contained 75% of predicted energy needs. The diets were then followed by a maintenance phase of one year.

Weight loss at 34 weeks and weight maintenance at 86 weeks was significantly better on PCD versus SD. Approximately 40% of the PCD participants lost at least 5% of their initial weight compared with only 12% of those on the standard diet. Significant improvements in biochemical and metabolic measures were observed at 34 weeks in both groups. The ease and self-reported adherence to the diet were greater in the PCD group throughout the study.

In this study, a diet using portion-controlled meal replacements resulted in significantly greater initial weight loss and less regain after one year of maintenance than a standard, self-selected, food-based diet. As PCDs may help obese patients with type 2 diabetes adhere to a weight control program, diabetes educators should consider recommending them as part of a comprehensive approach to weight control.

Recommended healthy diet USANA RESET

Cheskin LJ, et al. Efficacy of meal replacements versus a standard food-based diet for weight loss in type 2 diabetes: a controlled clinical trial. 2008. Diabetes Educ 34(1):118-27

High Glycemic Load Diets Increase Risk of Age-Related Hearing Loss

2011-01-01T10:25:00.000-08:00

In a recent study of adults over 50 years old, those with a high glycemic load diet had a significantly increased risk of age-related hearing loss.

Age-related hearing loss is a common disability in older adults, and nutrition may play a role in the development of this condition. Carbohydrate nutrition is thought to possibly relate to age-related hearing loss.

In a recent issue of the Journal of Nutrition, researchers sought to determine the association between glycemic index (GI) and glycemic load (GL) and age-related hearing loss.

Hearing loss was measured in 2956 participants aged 50 years or older enrolled in the Blue Mountains Hearing Study. Food frequency questionnaires were used to document intakes of carbohydrates, sugar, starch, cereal and total fiber. Australian GI values were used to calculate average GI and GL values of the diets.

A higher average dietary GI was associated with a 59% increased prevalence of any hearing loss. Participants in the highest 25% of average dietary GL intake compared with those in the lowest 25% had a 76% greater risk of developing hearing loss. Higher carbohydrate and sugar intakes were also associated with occurrence of hearing loss.

In this study group, a high-GL diet was a predictor of hearing loss, as was higher intake of total carbohydrates. It is possible that prolonged high blood glucose levels after a meal may be an underlying biological mechanism in the development of age-related hearing loss.

Gopinath B, et al. Dietary Glycemic Load Is a Predictor of Age-Related Hearing Loss in Older Adults. 2010. J Nutr 140(12):2207-12.

High Protein, Low-Glycemic Diets Better at Maintaining Weight Loss

2011-01-01T10:17:00.000-08:00

New research shows that a low-glycemic diet relatively high in protein is more effective at weight maintenance than a low-protein, high-glycemic diet.

A recent study in the New England Journal of Medicine reports that a diet relatively high in protein and low in refined carbohydrates (low-glycemic) is more successful than other diets at maintaining weight loss.

Researchers enrolled overweight adults from eight European countries who had lost at least 8% of their initial body weight with a low-calorie diet. Participants were randomly assigned to one of five diets to prevent weight regain over a 26-week period: a low-protein and low-GI (glycemic index) diet, a low-protein and high-GI diet, a high-protein and low-GI diet, a high-protein and high-GI diet, or a control diet based on the current European dietary recommendations. The high protein diet provided 25 percent of calories in the form of protein, while the low protein diet consisted of 13 percent protein.

Five hundred forty-eight subjects completed six months on the assigned diets. In the analysis of participants who completed the study, only the low-protein/high-GI diet was associated with subsequent significant weight regain (1.67 kg, or 3.6 lbs) by the end of the dietary intervention. Weight regain was less in those who consumed high protein compared to low protein and in low-GI diets compared to high-GI diets. High-GI foods include white flour, white rice, and other refined carbohydrates.

This study shows that a modest increase in protein content and a modest reduction in glycemic index can lead to an improvement in compliance and maintenance of weight loss.

Larsen TM, et al. Diets with High or Low Protein Content and Glycemic Index for Weight-Loss Maintenance. 2010. N Engl J Med 363:2102-13.

Low Vitamin D Levels May Increase Heart Disease Risk

2011-01-01T10:04:00.000-08:00

A study published in the journal Circulation showed that low levels of vitamin D may increase the risk of cardiovascular events, including heart attack, heart failure, or stroke. Individuals with both hypertension and low vitamin D levels had nearly double the risk of cardiovascular problems.

Interest in vitamin D has been increasing in recent months with a growing number of studies linking the vitamin to protection against osteoporosis and certain cancers. There is also evidence that a higher intake of vitamin D may be helpful with regard to high blood pressure, fibromyalgia, diabetes mellitus, multiple sclerosis, and rheumatoid arthritis

In a population-based study, researchers used data from 1739 participants in the Framingham Offspring Study to study the relationship between vitamin D levels and cardiovascular health risk. Although vitamin D levels above 30 ng/mL are considered optimal for bone metabolism, only 10 percent of the participants had levels in this range. In fact, 28 percent had blood levels lower than 15 ng/mL. Participants with levels below 15 ng/mL had a 62 percent greater chance to develop cardiovascular events than those with higher levels. People with low vitamin D levels and high blood pressure (> 140/90 mmHg), were found to have double the risk of cardiovascular problems compared to people with normal blood pressure and vitamin D levels.

Vitamin D is produced in the skin on exposure to UVB radiation (sunlight) and obtained in the diet from foods like oily fish, egg yolk, and liver. Recent studies have shown, however, that sunshine levels in some northern countries are so weak during the winter months that the human body makes little to no vitamin D, leading to widespread deficiencies. In addition, increased skin pigmentation also reduces the effect of UVB radiation, meaning darker skinned people are at greater risk.

The results from this study raise the possibility that treating vitamin D deficiency, by supplementation and/or lifestyle measures, could reduce the risk of cardiovascular events.

Wang TJ, et al. Vitamin D Deficiency and Risk of Cardiovascular Disease. 2008. Circulation 117(4):503-11

Long Term Multivitamin Use in Women Reduces the Risk of Heart Attack

2010-12-09T12:25:00.000-08:00

A new study published in the American Journal of Clinical Nutrition examined the association between multivitamin use and myocardial infarction (MI) in a large population of women.

The study included 31,671 Swedish women with no history of cardiovascular disease (CVD) and 2,262 women with a history of CVD aged 49–83 years. At the beginning of the study, the women completed a questionnaire regarding dietary supplement use, diet, and lifestyle factors. Multivitamins were estimated to contain nutrients close to recommended daily allowances.

During an average of 10.2 years of follow-up, 932 MI cases were identified in the CVD-free group and 269 cases in the CVD group. In the CVD-free group, use of multivitamins only, compared with no use of supplements, was associated with a 27% decreased risk of CVD. When multivitamins were used in conjunction with other supplements, the risk of CVD was decreased by 30%. In those that used only supplements other than multivitamins the reduction in risk was much smaller at only 7%. In women that used multivitamins for more than 5 years there was a 41% reduction in risk of CVD.

This research showed that the use of multivitamins was inversely associated with MI, especially among long-term users with no history of CVD.

Rautiainen S, Akesson A, Levitan EB, Morgenstern R, Mittleman MA, Wolk A. Multivitamin us and the risk of myocardial infarction: a population-based cohort of Swedish women. 2010. American Journal of Clinical Nutrition, Vol. 92, (5), 1251-6

High Fish & Vegetable Intake Reduces Risk of Breast Cancer

2010-11-26T08:01:00.000-08:00

In a new study, researchers found a strong correlation between a diet high in vegetables and seafood and reduced risk of breast cancer. Lower BMI, high levels of dietary supplement use, and increased physical activity also correlated with reduced breast cancer risk.
After skin cancer, breast cancer is the most common type of cancer in women. In U.S. women, more than 1 in 4 cancers (28%) are breast cancers. Historically, breast cancer has been much more prevalent in Western countries than in Asian countries, although the gap has declined dramatically in recent years. A new study published by researchers at South Korea's National Cancer Center sheds new light on one possible explanation for this effect.

In this study, 357 breast cancer patients between the ages of 25 and 77 were matched with 357 healthy controls. A trained dietitian conducted face-to-face interviews with each study subject, collecting detailed information on lifestyle (including physical activity), demographics, and diet.

410 types of reported food were grouped into 39 food groups based on nutrient profiles and culinary usage. These food groups were then used to calculate two "dietary patterns": one characterized by regular consumption of a variety of vegetables, seafoods, and soybean products, and another characterized by above-average intake of meat (non-fish) and starch-rich foods (bread, noodles, pizza, etc). The "vegetable-seafood" diet is representative of a traditional Korean diet, while the "meat-starch" diet is representative of a traditional Western diet. Statistical analysis were then performed to look for correlations between demographics, lifestyle factors, and these two diet patterns.

Breast cancer occurrence in this study correlated strongly with higher BMI (p=0.006), lower levels of dietary supplement use (p=0.005), and low levels of physical activity (p=0.021). Additionally, a significant inverse association was seen between the vegetable-seafood pattern and breast cancer risk, while no correlation (positive or negative) was seen for the meat-starch group. Additional analysis correlated the vegetable-seafood diet with higher intakes of fiber, vitamin A, carotene, vitamin C, vitamin E, folate, and calcium (p < 0.001 for all).

This study provides strong evidence for a diet high in vegetables and seafood reducing the risk of breast cancer. As the authors note, the increasing Westernization of Korean diets may explain - at least in part - the rising rates of breast cancer in that country.

Cho YA, Kim J, Shin A, Park KS, Ro J. Dietary Patterns and Breast Cancer Risk in Korean Women. 2010. Nutrition and Cancer 62(8):1161-9.

New Diabetes Projections "Paint Sobering Picture of the Future"

2010-11-19T19:41:00.000-08:00

Without widespread intervention, one in three American adults could have type 2 diabetes by the year 2050.

Type 2 diabetes is a chronic health condition that develops when the body becomes resistant to insulin, a hormone that regulates carbohydrate and fat metabolism. The exact mechanism by which type 2 diabetes occurs is unknown, but a number of correlating risk factors - particularly obesity and physical inactivity - are well-established. Unfortunately, the number of individuals with type 2 diabetes has increased sharply in recent years, with an estimated $174 billion cost to the United States in 2007 alone.

A number of papers have attempted to project type 2 diabetes prevalence 5, 10, and 20+ years into the future. Unfortunately, most of these projections have relied on weak or outdated metrics, including old census data, static mortality rates, and overly simple estimations of diabetes incidence. A recent paper from researchers at the National Center for Chronic Disease Prevention and Health Promotion hoped to overcome these weaknesses by utilizing recent census data and a matrix of factors derived from an extensive literature review.

The researchers describe their results as "a sobering picture of the future growth of diabetes." Their most optimistic values point to 21% of the U.S. adult population having type 2 diabetes in the year 2050. A middle-ground scenario predicts a prevalence of 25%-28%, while high-end data points to a diabetes prevalence of 33%, or 1 in 3 adults. To put these numbers in perspective, approximately 7% of the U.S. adult population had type 2 diabetes in 2007. In 1990, prevalence was below 5%.

Unlike some chronic diseases, type 2 diabetes risk can be reduced by relatively moderate lifestyle changes. Losing weight (if overweight or obese), improving dietary choices, and regular exercise are all known to reduce risk of acquiring type 2 diabetes. The authors of this paper note that such changes "can help to decrease loss in quality of life and the future cost of providing care for people with diabetes. Indeed, such efforts are essential if we hope to moderate or slow the growth of diabetes prevalence."

Boyle JP, Thompson TJ, Gregg EW, Barker LE, Williamson DF. Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence. 2010. Population Health Metrics 8:29

Regular Exercise Reduces Risk of the Common Cold

2010-11-16T18:15:00.000-08:00

New research shows a strong correlation between regular aerobic exercise and reduced risk of upper respiratory tract infections.

Upper Respiratory Tract Infections (URTI) can be caused by more than 200 different viruses, and it is estimated that the U.S. population suffers more than one billion colds a year (2-4 per average adult, 6-10 per average child). A number of lifestyle factors contribute to URTI risk, including poor nutrient status, lack of sleep, and stress. A new paper published in the British Journal of Sports Medicine adds exercise habits to the list of lifestyle factors affecting URTI risk.

1,023 subjects between 18 and 85 years of age were recruited for this study, with 1,002 individuals completing all study requirements. Subjects were selected from multiple BMI groups (roughly one-third were of normal weight, one-third were overweight, and one-third were obese) to ensure adequate representation. A comprehensive validated survey on lifestyle, diet, activity levels, stress, and URTI incidence and severity was completed by each study participant.

After controlling for potential cofounders, total days with URTI symptoms were 43-46% lower in the highest third of aerobic activity when compared to the lowest third, while URTI severity was reduced 32-41% for the high group. Low stress levels, high exercise frequency (≥5 days/week), and high fruit intake (≥3 servings/day) also correlated with reduced URTI incidence.

The exact mechanism by which aerobic exercise reduces URTI risk is still uncertain, although it appears to be a combination of factors, including transient increases of certain immune cell types, a reduction of stress hormones, and specialized benefits to key organs (particularly the lungs, which serve as a primary barrier against URTIs).

Nieman DC, Henson DA, Austin MD, Sha W. Upper respiratory tract infection is reduced in physically fit and active adults. 2010. Br J Sports Med, ePub ahead of print. doi:10.1136/bjsm.2010.077875

Soy Phytates

2010-11-15T20:16:00.000-08:00

Plants store phosphorus, an essential nutrient for plants and animals, in their seeds to support the growth of young seedlings. This phosphorus is stored in the form of phytate (inositol hexametaphosphate). Plant phytates are considered by some to be “anti-nutrients” because phytates consumed in the human diet can complex with essential minerals like iron and zinc and inhibit absorption in the gut. Others, however, consider phytates to be important food constituents that act not only as natural food-preserving antioxidants, but also help reduce risk of heart disease and cancer in those who consume whole grains, beans, seeds and nuts.

Soybeans contain significant amounts of phytate (1.3-1.4%), and some point to this as a reason to avoid soy foods. However, it is important to note that most whole grains, beans, seeds, and nuts are also rich in phytates (Table 1), and there is a wealth of science to support the fact that these foods are important constituents of a healthy, well-balanced diet that supports longevity and reduced disease risk. As such, it is difficult to argue that soy should be avoided based on its phytate content when so many healthy foods contain comparable levels of phytates.

It is also important to note that on a percent basis, isolated soy protein contains far less phytate than do whole soybeans.

Table 1. Phytate contents of some common grains, beans, and nuts. Values from NR Reddy and SK Sathe (eds). Food Phytates. CRC Press, 2001.

Food	Phytate Content (%)
Whole Wheat	0.7-1.1
Wheat Flour	0.3-1.4
Wheat Bran	2.0-5.3
Corn	0.8-1.0
Oats	1.0
Barley	1.0
Brown Rice	0.9
Soybeans	1.3-1.4
Soy Protein Isolates	0.7-0.9
Kidney Beans	2.6-2.9
Lentils	0.4-0.5
Chick Peas	0.6
Small White Beans	1.2
Great Northern Beans	2.6-2.9
Peas	0.8-1.2
Hazel Nuts	1.9
Walnuts	0.6-2.4
Almonds	1.3-3.2
Cashews	0.6-2.0

Soy and Thyroid Function

2010-11-15T20:09:00.000-08:00

Some claim that soy foods should be avoided because they contain compounds (isoflavones) that disrupt thyroid function. We view this as a “half truth” that has little relevance for healthy individuals who consume soy at moderate levels as part of a healthy, balanced diet.

The relationship between soy consumption and thyroid function has been studied for more than 70 years. Interest in the topic grew during the 1950’s and 1960’s when several cases of goiter were identified in infants who consumed soy formulas. Subsequently, using in vitro and animal research, scientists found that at high concentrations the soy isoflavones genistein and daidzein can inhibit the activity of thyroid peroxidase and 5'-deiodinase, key enzymes involved in thyroid hormone biosynthesis.

Since that time, 14 human clinical trials have evaluated the effects of soy foods and soy isoflavones on thyroid function. All involved presumably healthy subjects, and with few exceptions the soy product used was isolated soy protein.

With only one exception, all of the studies showed either no effects or minor and clinically irrelevant effects of soy on thyroid function. The one trial that noted marked anti-thyroid effects (and the one often cited in anti-soy literature) involved Japanese adults who were fed roasted soybeans that had been pickled and stored in rice vinegar. The soy protein and isoflavone content of this food was not characterized, and the study involved no control group. As such, its relevance must be questioned.

One large study evaluated the specific effects of soy isoflavone supplements on thyroid function. Postmenopausal women between the ages of 64 and 83 were given daily doses of 90 mg of soy isoflavones or a placebo. Thyroid hormone levels were tested at baseline and again at 90 and 180 days. After six months, any differences in thyroid hormones between the groups were statistically indistinguishable.

Today, most experts agree that soy foods and isolated soy protein have little if any effect on thyroid function in normal, healthy adults. That said, the potential for soy isoflavones to disrupt thyroid function should not be ignored by people who have compromised thyroid function and/or people with suboptimal iodine status. But these groups aside, we contend that soy is a good source of protein when consumed in moderate amounts as part of a healthy, balanced diet.

In support of this position, note that Asian populations have a long history of consuming soy products without significant occurrence of goiter. This also holds true for vegetarians who consume not only higher levels of soy, but high levels of fruits and vegetables that contain other flavonoids known to inhibit thyroid enzyme activity. These flavonoids include kaempferol (found in apples, onions, green tea), naringenin (found in citrus fruits), and quercetin (found in fruits and berries). Such compounds are widely distributed in plant-derived foods and are consumed at relatively high levels (up to 1 gram or more per day) by vegetarians and vegans. Despite this, vegetarian diets have not been linked with decreased thyroid function.

Serum 25-Hydroxyvitamin D Concentrations

2010-11-10T10:08:00.000-08:00

Serum concentration of 25(OH)D is the best indicator of vitamin D status. It reflects vitamin D produced cutaneously and that obtained from food and supplements and has a fairly long circulating half-life of 15 days. However, serum 25(OH)D levels do not indicate the amount of vitamin D stored in other body tissues. Circulating 1,25(OH)₂D is generally not a good indicator of vitamin D status because it has a short half-life of 15 hours and serum concentrations are closely regulated by parathyroid hormone, calcium, and phosphate. Levels of 1,25(OH)₂D do not typically decrease until vitamin D deficiency is severe.

There is considerable discussion of the serum concentrations of 25(OH)D associated with deficiency (e.g., rickets), adequacy for bone health, and optimal overall health (Table 1). A concentration of <15 nanograms per milliliter (ng/mL) (or <37.5 nanomoles per liter [nmol/L]) is generally considered inadequate; concentrations >15 ng/ml (>37.5 nmol/L) are recommended. Higher levels are proposed by some (>30 ng/ml or >75 nmol/L) as desirable for overall health and disease prevention, but insufficient data are available to support them. Serum concentrations of 25(OH)D consistently >200 ng/ml (>500 nmol/L) are potentially toxic.

Table 1: Serum 25-Hydroxyvitamin D [25(OH)D] Concentrations and Health*

ng/mL**	nmol/L**	Health status
<10-11	<25-27.5	Associated with vitamin D deficiency, leading to rickets in infants and children and osteomalacia in adults
<10-15	<25-37.5	Generally considered inadequate for bone and overall health in healthy individuals
≥15	≥37.5	Generally considered adequate for bone and overall health in healthy individuals
Consistently >200	Consistently >500	Considered potentially toxic, leading to hypercalcemia and hyperphosphatemia, although human data are limited. In an animal model, concentrations ≤400 ng/mL (≤1,000 nmol/L) demonstrated no toxicity.

* Serum concentrations of 25(OH)D are reported in both nanograms per milliliter (ng/mL) and nanomoles per liter (nmol/L).
** 1 ng/mL = 2.5 nmol/L

An additional complication in assessing vitamin D status is in the actual measurement of serum concentrations of 25(OH)D. Considerable variability exists among the various assays available and among laboratories that conduct the analyses. This means that compared to the actual concentration of 25(OH)D in a sample of blood serum, a falsely low or falsely high value may be obtained depending on the assay or laboratory used. A standard reference material for 25(OH)D became available in July 2009 that will now permit standardization of values across laboratories.

What is Choline

2010-11-07T12:35:00.000-08:00

Choline is a dietary component necessary for cell membrane integrity and facilitating the movement of fats into and out of cells. Choline is also a precursor for acetylcholine, an important neurotransmitter in the brain. Choline also works with folic acid, vitamin B12, and methionine in methyl group metabolism and maintenance of healthy homocysteine levels. Since high levels of homocysteine increase the risk of cardiovascular disease, an adequate intake of choline may be important in reducing risk.

Pregnancy and lactation are periods when maternal reserves of choline risk becoming depleted. Because the availability of choline for normal fetal development of the brain is critical, expectant and nursing mothers should make certain their choline intake is adequate.

Although choline can be found in a wide variety of foods, some of the richest sources are foods high in cholesterol and fat (e.g. beef liver). Because many Americans have been advised to decrease their consumption of fatty foods, choline intake in some populationi groups may be inadequate. Healthy sources of choline include Brussel sprouts, broccoli, eggs, lean beef, milk, peanuts, and certain seafoods (shrimp, salmon, and cod).

High Vitamin B Levels Associated With Reduced Risk of Colorectal Cancer

2010-11-03T20:20:00.000-07:00

In a recent population-based European study, individuals with higher vitamin B2 and B6 levels had significantly decreased risks of colorectal cancer.

New research reported in the October 2010 issue of Cancer Epidemiology, Biomarkers and Prevention shows a correlation between higher levels of vitamins B2 (riboflavin) and vitamin B6 and a reduced risk of developing colorectal cancer. B-vitamins are essential for metabolism and have been linked to a reduced risk of colorectal cancer in previous studies. Since associations with the B-vitamin folate have been studied most often, researchers in the current study focused on potential associations of other B vitamins (B2, B6, and B12) and colorectal cancer.

This European population-based study included subjects who were participants in the Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The study included 1,365 adults diagnosed with colorectal cancer and 2,319 age and gender-matched control subjects. Blood samples were taken at enrollment and analyzed for vitamins B2, B6, and B12, as well as 8 variants of genes that relate to the function of these vitamins.

After an average follow-up of 3.6 years, individuals whose vitamin B6 levels were among the top 20 percent of participants had a 32 percent lower risk of developing colorectal cancer when compared to those whose levels were in the lowest 20 percent. Among those whose vitamin B2 levels were highest, the risk was 29 percent lower than those whose levels were lowest. There were no significant associations for vitamin B12 and colorectal cancer. Vitamin levels were lower in smokers compared to nonsmokers, and the benefits for vitamin B6 were stronger in males who consumed ≥30 g (one ounce) of alcohol per day.

This research is the first population-based study to indicate that vitamin B2 is inversely associated with colorectal cancer, and it supports previously suggested inverse associations of vitamin B6 with colorectal cancer.

Simone J.P.M. Eussen et al. Vitamins B2, B6, and B12, and Related Genetic Variants as Predictors of Colorectal Cancer Risk. Cancer Epidemiol Biomarkers Prev; 19(10); 2549–61.

Folic Acid (Vitamin B9)

2010-11-01T17:34:00.000-07:00

Folic acid is a water-soluble B vitamin with a role as a regulating coenzyme for cellular metabolism and cell division.

Folic acid helps form the building blocks of DNA and RNA needed for protein synthesis in human cells. Rapidly growing tissues - such as those of a fetus - and rapidly regenerating cells - like red blood cells and immune cells - have an especially high need for folic acid.

Folic acid requirements increase during pregnancy. Deficiencies of folic acid during pregnancy are associated with low birth weight and an increased incidence of neural tube defects, including anencephaly and spina bifida. In one study, women at high risk of giving birth to babies with neural tube defects lowered their risk by as much as 72% by taking folic acid supplements prior to and during pregnancy. Medical experts, other healthcare professionals, and the March of Dimes recommend that all women of childbearing age supplement with 400 mcg of folic acid per day. Such supplementation would protect against the formation of neural tube defects during the time between conception and when pregnancy is discovered. If a woman waits until after pregnancy to begin taking folic acid supplements, it is likely too late to prevent a neural tube defect.

Folic acid deficiency has also been associated with high homocysteine levels and an increased risk for stroke, heart disease, and cognitive diseases like Alzheimer's disease. A folic acid deficiency may also result in a form of anemia (which can be remedied with supplementation).

It is difficult to accurately estimate how much folic acid is present in food. The best food sources appear to be vegetables (asparagus, broccoli, brussels sprouts, legumes), nuts, and seeds.

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Soy and Weight Loss

2010-10-30T12:40:00.001-07:00

Some claim that soy-based meal-replacement formulas are ineffective for weight loss. However, the fact is that soy protein has been used effectively as a component of weight loss diets for more than 20 years. Animal studies have shown that soy protein and its associated bioactive isoflavones and peptides can have beneficial effects on glucose metabolism, fat metabolism, insulin sensitivity, metabolic rate, food intake and weight loss. Studies in humans have further shown that increased intakes of soy or animal protein can increase metabolic rate, decrease appetite, and increase satiety. Furthermore, randomized clinical trials and clinical weight loss studies have shown that diets based on soy protein are every bit as effective - if not more effective - than diets based on dairy protein when it comes to helping people lose weight and abdominal fat.

The truth is that weight loss is much more a function of reducing caloric intake and increasing calories burned through exercise, as opposed to simply using soy or whey protein in the diet.

The Nutritional Value of Soy Protein

2010-10-30T12:37:00.000-07:00

Several scales for assessing the nutritional value of protein have been developed over the years. These have been used to rate various proteins for their ability to support growth, supply important amino acids, and generally satisfy the human protein requirement. The first broadly accepted standard was the Protein Effectiveness Ratio (PER). Developed in 1919, this method focused on the growth-supporting characteristics of a given protein, and it used rats (rather than humans) as the test animal. Because of the metabolic differences between rodents and humans, this method has been largely discredited and is rarely used today.

A second method, the Biological Value (BV) scale, is based on the retention of protein nitrogen by the body. It is thought to be a good measure of protein utilization. The BV scale stretches from 0 to 100, with a score of 100 indicating that virtually 100% of a given protein's nitrogen is retained by the body. Some people - particularly in the sports world - use this method, but it is not widely accepted within the community of nutritional scientists.

Most nutritionists (and many in the sports sector) now consider the Protein Digestibility Corrected Amino Acid Score (PDCAAS) to be the international standard for assessing protein quality. This approach, developed by the Food and Agriculture Organization and endorsed by the U.S. Food and Drug Administration, considers the amino acid balance of a given protein as it compares with the amino acid needs of humans, with specific reference to 2-5 year old children. It also takes into account the digestibility of the protein, or how fully the protein is broken down and absorbed by the body. The PDCAAS scale stretches from 0.0 to 1.0, with a score of 1.0 indicating that the protein completely satisfies human needs from a quality perspective.

During the 1990’s, whey protein became the protein of choice among bodybuilders, due in large part to an intense and successful marketing campaign sponsored by the dairy industry. That marketing promotion was based on the fact that some whey protein isolates have a rating of 100 on the BV scale. In comparison, egg-white protein (the traditional standard for bodybuilders) typically ranks in the 90’s, while most fish, beef, and soy proteins rank in the 70’s on the BV scale. (You will see a wide variety of BV scores for these foods because different people express the ratios in different ways, and the techniques for measuring BV are imprecise and not easily replicated from one experiment to another.)

However, when the PDCAAS approach is employed, soy protein isolates, whey protein isolates, and egg white protein all score a complete 1.00, meaning they all exhibit very high - and essentially equivalent - nutritional value in supporting human health.

The high PDCAAS score for soy protein isolates speaks to two important points. First, soy protein is well-digested and absorbed by humans. (This is the “D” of PDCAAS). Second, soy protein is complete. It contains all the essential amino acids in a proper balance for human growth, development, and health. (This is the “AA” of PDCAAS.)

Some authors have claimed that soy is lacking in the essential amino acid methionine, as if to imply that soy contains no methionine. This is incorrect. Soy may not be rich in methionine, but it contains enough to supply human needs under most circumstances. Furthermore, it is important to point out that human methionine requirements can be partially met by another sulfur-containing amino acid (cysteine). When cysteine + methionine content is considered, soy protein is nutritionally excellent.

Soy Allergies and Sensitivities

2010-10-30T12:35:00.001-07:00

Soy is on the Food and Agriculture Organization’s list of the eight most prevalent food allergens. This list includes milk, eggs, fish, crustacea, wheat, peanuts, tree nuts, and soy. Together, these foods account for about 90% of food allergies.

That said, it is important to understand that these high-profile food allergies differ widely in their incidence, severity, and symptoms, and that soy protein - relative to milk and nut proteins, for example - is a relatively mild allergen. Consider the following:

Milk and peanut allergies are each 5-6 times more prevalent than soy allergies. In fact, the true incidence of soy allergy - as confirmed by double blind, placebo-controlled food challenges - is quite low. Research indicates that allergic reactions to soy occur predominately in children less than four years of age, and most estimates agree that <1.0% of children (probably 0.2-0.4% of children) have true soy allergies. Moreover, 90% of children who have reactions to soy outgrow the allergy by age four. Given these statistics, it is safe to assume that <0.1% of adults (fewer than 1 in 1,000) are allergic to soy.
Food allergen reaction thresholds, or the minimum oral dose of protein that elicits an allergic response, tend to be several orders of magnitude (more than 100-1000 times) higher for soy than for milk and peanut proteins. In other words, it takes 100-1000 times more soy protein than milk or peanut protein to initiate an allergic response in sensitive people.
Soy allergies tend to produce mild symptoms relative to other food allergies. In a summary report of clinical food challenge studies, it was noted that in 80% of reported cases, symptoms of soy allergies were minimal to mild, with the remaining 20% being moderate. No severe allergic reactions to soy were reported. In comparison, milk and peanut allergies produced minimal-to-mild symptoms in 50-70% of cases, moderate symptoms in 20-30% of cases, and severe symptoms in 10-15% of cases.

In summary, soy proteins can produce allergic reactions in some people, but relative to milk, peanut, and the other high-profile food allergens, reactions to soy are less common, more difficult to trigger, and less severe.

Beyond true allergic reactions, some people may be sensitive to the “non-digestible” sugars and fiber in soy. These components can cause abdominal bloating and gas, just like the sugars and fibers in most beans and just like the lactose in milk. Such symptoms are generally reduced, if not eliminated, when people use highly refined soy protein isolates which are 90-92% soy protein and only 3-4% carbohydrate (fiber plus simple and complex sugars and starches).

Alpha Lipoic Acid

2010-10-30T11:56:00.000-07:00

Alpha lipoic acid (ALA), also known as lipoic acid (LA) or thioctic acid, is a vitamin-like antioxidant. Some refer to ALA as the "universal antioxidant" because it has the unique attribute of being both fat and water-soluble. Another unique aspect of ALA is its ability to regenerate other antioxidants back to active states, including vitamin C, vitamin E, glutathione, and Coenzyme Q10.

Several experimental and clinical studies have shown potential therapeutic uses for alpha lipoic acid in addressing diabetes, atherosclerosis, cataracts, heavy metal poisoning, neurodegenerative diseases, and HIV infection.

Alpha lipoic acid is produced naturally by most organisms, including humans. It is also present in many foods, with above-average amounts in organ meats (kidney, heart, liver), potatoes, spinach, and broccoli. Unfortunately, total dietary availability of ALA is quite poor. One of the first groups of researchers to isolate alpha-lipoic acid required nearly 10 tons of liver residue to produce a mere 30mg of crystalline LA. Because of this, all supplemental ALA is produced synthetically.

Currently no RDI value has been set, nor has the issue been adequately studied. Some researchers believe that the amount needed for therapeutic antioxidant activity exceeds that produced by our bodies or consumed in a normal diet. As such, alpha lipoic acid is a strong candidate for dietary supplementation. Maintenance doses of 10-25 mg per day have been suggested, while doses up to several hundred milligrams per day have been used therapeutically.

Vitamin C (Mineral Ascorbates)

2010-10-30T11:49:00.000-07:00

Vitamin C, also known as ascorbic acid or ascorbate, plays two important roles in the body. First, it is a cofactor or cosubstrate for eight enzyme systems involved in various functions, including collagen synthesis, ATP synthesis in mitochondria, and hormone biosynthesis. Second, vitamin C is a powerful water-soluble antioxidant with a vital role in protecting cells and tissues from damaging oxidizing agents, including superoxides, hydroxyl radicals, and other free radicals. All these functions derive from one fundamental property: vitamin C is a powerful reducing agent (or electron donor) capable of neutralizing reactive oxidants.

Related functions performed by vitamin C include regenerating vitamin E to its active state, promoting iron absorption in the intestines by keeping iron in its reduced form, and participation in DNA transcription and protein synthesis regulation.

The richest dietary sources of vitamin C include cantaloupe, grapefruit, honeydew, kiwi, mango, oranges and other citrus fruits, strawberries, and watermelon. The richest vegetable sources include asparagus, broccoli, brussels sprouts, dark green leafy vegetables, and peppers.

Although vitamin C is generally non-toxic, very high dosages (several grams or more) may cause or contribute to gastrointestinal distress and diarrhea.

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What is Elemental Calcium

2010-10-28T17:47:00.000-07:00

Due to its high reactivity, calcium is rarely found in its elemental (or pure) state in nature. Similarly, you cannot buy pure calcium; it is always combined with another element to make it less reactive. During digestion, your body breaks the combination of calcium and other elements apart to make the calcium available for absorption.

What this means is that a 500 mg calcium supplement tablet may not be 500 mg of calcium, but a 500 mg mixture of calcium and other elements. The actual amount of usable calcium in a supplement is called elemental calcium.

Check out this hub: Do Calcium Supplements Cause Kidney Stones and Constipation for more information about Calcium

Beta-Carotene & Vitamin A

2010-10-28T17:27:00.000-07:00

Carotenoids comprise a diverse class of antioxidant molecules that help protect the body from oxidative damage. Approximately 700 natural carotenoids have been isolated and characterized. Most are derived from plants, where they serve multiple functions: photosynthetic pigments, photoprotectants, and free radical scavengers. Some 50-60 carotenoids are present in a typical diet with the major sources being fruits and vegetables.

Beta-carotene is one of the best known carotenoids, likely because: (1) it is one of the most abundant in a typical adult diet, and (2) it provides two nutritional functions - in addition to its role as an antioxidant, the human body converts beta-carotene into vitamin A.

Other members of the antioxidant carotenoid family include alpha-carotene, cryptoxanthin, zeaxanthin, lutein, and lycopene. Unlike beta-carotene, most of these nutrients are not converted to vitamin A in significant amounts.

Beta carotene's role as an antioxidant is based on its extensive system of conjugated double bonds which, upon reacting with an oxygen atom, absorb and diffuse that oxygen's potentially destructive energy. The oxygen atom returns to a lower energy state, and beta carotene dissipates the absorbed energy harmlessly (as heat). Similar mechanisms are involved in quenching the oxidative potential of hydroxyl radicals and other free radical compounds.

As provitamin A, beta carotene contributes to an entirely different set of functions by supplying a portion of the body's requirement for retinol (vitamin A). In fact, a single molecule of beta-carotene can be cleaved in the body to produce two molecules of vitamin A. Other carotenoids (including alpha-carotene, gamma-carotene, and cryptoxanthin) provide provitamin A activity, but yield only one molecule of vitamin A when metabolized.

Retinol (vitamin A) is an essential nutrient associated with three important functions, the best-defined of which involves human vision. Retinol is a functional constituent of rhodopsin, a protein located in the retina of the eye that absorbs light and triggers a series of biochemical reactions that ultimately initiate nerve impulses, resulting in sight.

Secondly, vitamin A is involved in the activation of gene expression and the control of cell differentiation. It is through this function that vitamin A affects immune function, taste, hearing, appetite, skin renewal, bone development, and growth.

Vitamin A's third role involves control of embryonic development. Here it is thought that retinoic acid modulates the expression of certain genes that govern patterns of sequential development of various tissues and organs in the body.

Vitamin A deficiency is a major public health issue, particularly in developing countries. It has been estimated that 500,000 preschool-age children worldwide become blind each year as a result of vitamin A deficiency. Millions of others suffer from night blindness, a common clinical sign of inadequate vitamin A intake. Further estimates suggest that more than 100 million children worldwide suffer from vitamin A inadequacy without showing clinical signs of acute deficiency. Beta-carotene is known to be an effective dietary cure for vitamin A deficiency and an effective remedy for symptoms of this disorder.

Epidemiological studies support long-term beneficial effects of beta-carotene intake on a number of degenerative diseases. For example, the relationship between beta-carotene intake and cancer has received considerable attention in recent years. Epidemiological evidence suggests that long-term intake of dietary beta-carotene may reduce the risk of several types of cancer. Similar findings pertain to heart disease and immune health.

Dietary sources rich in beta carotene and other provitamin A carotenoids include carrots, broccoli, yellow squash, corn, tomatoes, papayas, oranges, and dark green leafy vegetables like spinach, kale and Chinese cabbage. Beta-carotene is heat stable, so it is not degraded during prolonged boiling or microwaving.

What is Coenzyme Q10

2010-10-28T16:11:00.000-07:00

Coenzyme Q10, or ubiquinone, is a compound with an essential role in mitochondrial electron transport, making it a fundamental part of cellular energy production.

Coenzyme Q10 is also an antioxidant. Its ability to quench free radicals helps maintain the structural integrity and stability of cell membranes (including intracellular membranes). It is also capable of improving oxidation resistance of low-density lipoprotein (LDL) cholesterol. Additional evidence suggests that Coenzyme Q10 uses its antioxidant capabilities to regenerate vitamin E.

CoQ10's other name, ubiquinone, signifies its ubiquitous (widespread) distribution in the human body. Highest levels of Coenzyme Q10 are found in the heart, liver, kidney, and pancreas.

CoQ10 supplementation has therapeutic benefits for several diseases. Some of the best-documented effects involve cases of heart failure, ischemic heart disease, certain muscular dystrophies, hypertension, and periodontal disease.

CoQ10 is synthesized in all cells of the body. It is also absorbed from food. Major sources of dietary CoQ10 include meats, fish, and vegetable oils (particularly soybean, sesame, and rapeseed oils). Vegetables are generally low in CoQ10, with the exception of spinach and broccoli.

As aging occurs, the body's ability to synthesize CoQ10 diminishes significantly. Deficiencies may also result from reduced assimilation from dietary sources.

Coenzyme Q10 supplements are generally considered safe and are best absorbed by the body when taken with foods. The usual maintenance dose is 10-30 mg per day, although higher doses are used therapeutically for the treatment of heart and blood vessel disease.

Maternal Vitamin B12 Levels Influence Cognitive Development in Children

2010-10-27T18:01:00.000-07:00

A recent study demonstrates an association between maternal vitamin B12 status during pregnancy and children's cognitive functioning at age 9. Higher maternal plasma vitamin B12 concentration in pregnancy was an independent predictor of the child's cognitive performance.

Vitamin B12 is an important nutrient for brain development and function. Since fetal requirements are provided by the mother through the placenta, inadequate maternal levels directly affect the amount available to the fetus. Research has consistently shown that maternal nutritional status can influence metabolic, cardiovascular, and psychiatric health of their future children.

In a recent study, investigators analyzed the relationship between maternal plasma vitamin B12 status during pregnancy and the child's cognitive function at 9 years of age. Previous research had shown that maternal vitamin B12 status influenced intrauterine growth and insulin resistance in children at 6 years of age.

Subjects included two groups of children born in the Pune Maternal Nutrition Study. The two groups were selected based on the maternal plasma vitamin B12 concentration at 28 weeks of gestation. Group 1 included 49 children born to mothers with the lowest plasma levels of vitamin B12. Group 2 included 59 children born to mothers with the highest plasma levels of B12.

The differences in tested intelligence and visual agnosia (the ability to recognize shapes, people, sounds, smells, and objects) were not significantly different between the groups. However, children from group 2 performed significantly better on a test for sustained attention and on a test of short-term memory. The differences were still significant after appropriate adjustments for confounding factors.

Result of this study support the idea that maternal vitamin B12 status in pregnancy influences cognitive function in offspring

Bhate V, et al. Vitamin B12 status of pregnant Indian women and cognitive function in their 9-year-old children. 2008. Food Nutr Bull 29(4): 249–54.

What is Magnesium

2010-10-27T13:53:00.000-07:00

Magnesium is an essential mineral for many fundamental processes in the body. It normally exists in the body as a charged particle (or ion) and is primarily stored in bones. Magnesium plays an integral role in hundreds of enzymatic functions and is important for nerve, muscle, and bone health.

Magnesium helps with the absorption of calcium and depends on vitamin D for its own absorption. Food dietary sources of magnesium include spinach, legumes, nuts, and grains.

The recommended dietary allowance for magnesium is 400 mg/d for men and 310 mg/d for women. Excessive intake can lead to gastrointestinal discomfort, but no adverse effect has been seen for long-term consumption of amounts less than or equal to 700 mg/d.

By the way, Magnesium silicate is used in tablet formulations as a glidant and anti-caking agent.

What is Phylloquinone (Vitamin K)

2010-10-26T10:58:00.000-07:00

Vitamin K (koagulation vitamin) is an essential nutrient required for the normal biosynthesis and activation of several key proteins. There are three forms of this vitamin.

Vitamin K1, also known as phylloquinone or phytonadione, is found in green plants and is the form included in dietary supplements.
Vitamin K2, also called menaquinone, is produced by bacteria, including some found in the human intestinal tract.
Vitamin K3 or menadione, a synthetic derivative, is used as a source of vitamin K in animal feeds.

Vitamin K is an essential cofactor for enzymatic activity. It assists in the enzymatic carboxylation of glutamic acid, an amino acid found in most proteins. This carboxylation occurs after the amino acid has been incorporated into the protein chain. The added carboxyl (-COOH) groups provide a site at which calcium can bind to the protein. Through the above activity, vitamin K is involved in converting an inactive precursor of prothrombin (blood coagulation factor II) into biologically active prothrombin.

Vitamin K is similarly involved in the synthesis of at least five other proteins involved in the regulation of blood clotting. In all cases, it is thought that vitamin K assists in activating these proteins through establishment of calcium-binding sites. Other vitamin-K-dependent proteins whose function depends on calcium binding have been identified in bone, kidney, and vascular tissues. In bone, these proteins appear to be involved in bone crystal formation and bone remodeling. As a result, the potential role of vitamin K in osteoporosis has received increasing attention.

The best food sources of vitamin K are green vegetables, including spinach, broccoli, Brussels sprouts, kale, and turnip greens.

No known toxicity is associated with the administration of high doses of the natural phylloquinone form of vitamin K.

Can someone on blood-thinning medication (aspirin, Plavix, Coumadin/Warfarin) take supplements containing vitamin K?

It is strongly recommended that anyone currently on Coumadin therapy discuss the use of vitamin K-containing supplements (including the Essentials, HealthPak, and Active Calcium) with their physician. Aspirin and Plavix, which both work by different mechanisms than Coumadin, are not affected by normal vitamin K intake.

Additional Resources:
Vitamin K - U.S. National Library of Medicine
Vitamin K - Physicians' Desktop Reference
Vitamin K - Wikipedia
Vitamin K - Linus Pauling Institute

What Are Possible Results of a Vitamin D Deficiency?

2010-10-25T19:55:00.000-07:00

What is Cholecalciferol (Vitamin D3)? Vitamin D is a fat-soluble nutrient essential for bone growth and general health. It is acquired through diet and exposure to sunlight. Light-induced synthesis occurs in the skin when ultraviolet light reacts with a form of cholesterol, converting it to vitamin D. This molecule is then altered by the liver and kidneys to form the physiologically active vitamin.

Several compounds have vitamin D or potential vitamin D activity. The most important forms are vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). The latter is the form normally found in humans, and it is also the form used in most nutritional supplements and clinical research.

A unique property of vitamin D is that it functions very much like a hormone. Its target tissues include the kidneys, intestines, and bones, where it helps regulate calcium and phosphorus homeostasis. Its specific activity in the intestines involves stimulating the synthesis of active transport proteins that mediate absorption of calcium. In bone tissue, vitamin D plays a role in regulating calcium deposition (bone mineralization) and mobilization. A role for vitamin D in immune system modulation is now under investigation.

Vitamin D is an essential component of bone health in both children and adults. Without vitamin D, bones do not calcify properly, leading to the condition known as "rickets." Vitamin D also plays an important role in tooth development. It is necessary for proper tooth eruption, growth, and strength. Through its role in regulating calcium and phosphorus metabolism, vitamin D plays a continuing role in maintaining a stable nervous system, normal heart activity, and normal blood clotting.

Exposure to the sun is the most important source of vitamin D for most humans. Limited amounts of vitamin D are available from food, including fortified milk, certain types of fish, and fortified breakfast cereals. Vitamin D deficiency is most directly related to poor bone health, including rickets and osteomalacia. However, vitamin D deficiency is also associated with an increased risk of other disorders, including certain cancers, type I diabetes, multiple sclerosis, tuberculosis, rheumatoid arthritis, muscle weakness and pain, depression, hypertension, and pregnancy complications. While many of these associations are actively being researched to determine the extent of their connection with vitamin D deficiency, we currently know that vitamin D unquestionably exerts a significant influence on many body systems.

Calcium and Vitamin D Enhance Heart Health Benefits of Weight Loss

2010-10-25T19:07:00.000-07:00

Weight Loss & Heart Health

Weight loss and reduced waist circumference are related to an improvement in heart health and factors related to metabolic syndrome. According to recent research, supplementing with calcium and vitamin D during weight loss enhances heart health benefits in women with typically low calcium intakes.

Recent research has shown that overweight individuals with low calcium and dairy consumption are at increased risk of developing metabolic syndrome. These findings suggest that adequate calcium intake could create a healthier metabolic profile.

Canadian researchers investigated this issue by testing cardiovascular benefits of long-term calcium supplementation in women with low calcium intake. Healthy, overweight or obese women with a daily calcium intake of less than 800 mg/day were randomly assigned to one of two groups: a group consuming two tablets/day of a calcium + vitamin D supplement (600 mg elemental calcium and 200 IU vitamin D/tablet), or a group consuming placebo. Both groups completed a 15-week reduced calorie weight-loss program.

Significant decreases in LDL cholesterol levels, as well as the ratios of total to LDL and LDL to HDL were seen the calcium + vitamin D group. These changes were independent of changes due to fat loss and reduced waist circumference. A tendency for more beneficial changes in HDL cholesterol, triglycerides, and total cholesterol was also observed in the calcium+D group.

This was the first study to show that calcium and vitamin D enhance the beneficial effects of weight loss on cardiovascular risk factors in overweight women with typically low calcium intakes.

Major GC, et al. Supplementation with calcium + vitamin D enhances the beneficial effect of weight loss on plasma lipid and lipoprotein concentrations. 2007. American Journal of Clinical Nutrition 85(1): 54-9.