Why not to take a multivitamin

The National Institutes of Health sponsored a symposium in May, 2006 on Multivitamin/Mineral Supplements and Chronic Disease Prevention. Multivitamins do not include enough vitamin C, E, and calcium to meet the requirements for high levels, but do add significantly to the intake of potentially harmful substances like beta-carotene and selenium. Those who take multivitamins in the U.S. are generally those who eat the best diets. As they get nearly 100% of their RDAs from the diet, it is questionable whether the supplements is helpful or harmful, and the studies below indicate varied results. Many distinguished experts say taking a multivitamin is a bad idea, others believe that everyone should do it [Walter Willett, Bruce Ames]. Certainly many among the elderly and poor populations in our country have low intakes of a certain nutrients. Unfortunately, these are the people least likely to be taking a multivitamin.

Stampfer, M. J. and Rimm, E. B. , "Epidemiologic Evidence For Vitamin E In Prevention Of Cardiovascular Disease", Am. J. Clin. Nutr. 62(suppl): 1365S-9S (1995)

Figure 1: Risk of coronary heart disease in Nurses' Health Study according to use of multivitamins and vitamin E supplements.

Vitamin Use Relative Risk

No supplement 1.0

Multivitamin only 0.85

Vitamin E alone 0.40

Vitamin E + multivitamin 0.50

[Personal Health Corporation Conclusion: Multivitamins provide no protection from coronary heart disease and may actually elevate risk. Vitamin E (even in multivitamin) reduces risk. THEREFORE, ONE SHOULD TAKE VITAMIN E. ONE SHOULD NOT TAKE MULTIVITAMINS.]

Blot, W. J., Li, J., Taylor, P.R., Guo, W., Dawsey, S.M., and Li, B., "The Linxian Trials: Mortality Rates By Vitamin-Mineral Intervention Group", Am J Clin Nutr 62(suppl): 1424S-6S (1995)

"After multiple vitamin and mineral supplements were given for 6 y [in a clinical trial of 3318 people], reductions in total and cancer mortality ...were not significant."