Higher levels of vitamin D reduce the risk of multiple sclerosis

People with higher circulating vitamin D levels are significantly less likely to develop multiple sclerosis, according to a new study by Harvard researchers.

The RDA for vitamin D was recently increased in the elderly to 600 IU per day. Many reports and most experts suggest levels between 600-1,000 IU per day, especially for those in northern climates or with poor sunlight exposure. Typical dietary intake is between 100-200 IU per day.

A report published in the December 20, 2006 issue of the Journal of the American Medical Association concluded that having a higher serum level of vitamin D is associated with a lower risk of multiple sclerosis (MS) among men and women. The finding adds to those of previous studies that suggest that the vitamin may have a protective effect against the disease.

Harvard researchers studied more than 250 individuals diagnosed with multiple sclerosis between 1992 and 2004. The team determined that for every 50 nanomole per liter increase in serum vitamin D among white participants there was a 41 percent decrease in the risk of MS. Whites in the top one-fifth of serum vitamin D concentrations had the lowest risk of the disease, and those in the lowest fifth had the greatest risk. Those with the highest vitamin D levels experienced a 62 percent lower risk of MS compared to those in the group with the lowest levels.

The results of this study suggest that high circulating levels of vitamin D are associated with a lower risk of multiple sclerosis.

JAMA. 2006;296:2832-2838.

Inadequate vitamin levels may result in poor athletic performance

Active individuals with low Vitamin B intakes in may perform worse in high-intensity exercise and have a decreased ability to build and repair muscle. National B-Vitamin recommendations may be too low for active individuals. Athletes with poor or restricted diets should consider and multivitamin supplement.

Active individuals lacking in B-vitamins may perform worse during high- intensity exercise and have a reduced ability to repair and build muscle than individuals with nutrient-rich diets.

These B vitamins, which include thiamin, riboflavin, vitamin B6, B12 and folate, are necessary for the body to convert proteins and sugars into energy, and are used during the production and repair of cells, including red blood cells.

Researchers analyzed the diet and athletic performance of several elite and collegiate athletes, as well as less competitive individuals. Even a marginal deficiency in these nutrients negatively influenced their body's ability to repair itself, operate efficiently and fight disease. Exercise induced stress, the changes in body tissues resulting from training, increased loss of nutrients in sweat, urine and feces, and the additional nutrients needed to repair and maintain higher levels of lean tissue mass may all affect an individual's B-vitamin requirements.

The researchers noted that current national B-vitamin recommendations for active individuals may be inadequate, and that chronic deficiencies could jeopardize their abilities and long-term health. Athletes and individuals with poor and restricted diets should consider a multivitamin and multimineral supplement to ensure adequacy.

Kathleen Woolf; Melinda M. Manore Int J Sport Nutr Exerc Metab 2006(16) 5.

Safety of Multivitamins and Antioxidants

Nutritional supplements have been widely used and highly valued by American consumers ever since vitamins were discovered and commercialized, beginning in the early decades of the 1900's. According to recent national health survey, as many as 78 million Americans adults use multivitamins on a regular basis.

Multivitamin/mineral supplements are an effective means of delivering adequate amounts of most essential nutrients to help people achieve recommended intakes. The great majority of dietary supplements, including multivitamins, are safe for regular use. Despite widespread usage, there have been no specific published reports of toxicity or adverse effects associated with the use of multivitamins.

A series of well-publicized clinical trials conducted in diseased patients utilizing relatively high doses of single nutrients or combinations of nutrients (such as vitamin E and/or beta-carotene), have yielded disappointing results, and even suggested the presence of harm. However, those trials were conducted in patients with serious illnesses (ie. cancer or cardiovascular disease) who were on multiple medications or who were current heavy smokers. The results of these trials should be placed in context and are not applicable to the generally healthy population.

Advanced levels of antioxidants are a common thread among nearly every population that is less prone to premature chronic degenerative disease. The Japanese have high levels of fruit, vegetables, green tea and soy as part of their traditional diet. Vegetarians have lower levels of heart disease and cancer, compared to the typical mixed diet, likely in part due to higher intakes of antioxidants. While high levels of single nutrients and foods may pose a risk of danger and toxicity, there is no known unsafe intake level of total antioxidants in normally healthy individuals.