Dietary Supplements and Prevention of Chronic Disease:

 Insufficient Evidence

Findings from an NIH state-of-the-science conference on multivitamin/mineral supplements and chronic disease prevention

An NIH state-of-the-science conference on multivitamin and mineral supplements to prevent chronic disease generated a statement based on a systematic literature review, investigator presentations, public discussion, and panel deliberations. The panel of health professionals and public representatives found the following:

·                     Few trials of one or two vitamins found efficacy in preventing chronic disease.

·                     Smokers should avoid ß-carotene, based on evidence that it increased the incidence of  

·                     lung cancer and of death.

·                     Calcium and vitamin D can improve bone-mineral density and reduce fracture risk in               

·                     postmenopausal women.

·                     Results of single studies and examination of secondary outcomes suggest that: (1) 

       selenium may reduce risk for prostate, lung, and colorectal cancer; (2) vitamin E may reduce risk for heart disease in women and prostate cancer in male smokers; (3) vitamin A and zinc may decrease stomach cancer risk; (4) vitamin C, vitamin E, ß-carotene, and zinc may prevent progression of age-related macular degeneration.

·                     The current level of public assurance of the safety and quality of multivitamins is              

·                     inadequate, and the evidence is insufficient to recommend either for or against the use of   

·                     multivitamins to prevent chronic diseases.

Comment: Given that about one third of Americans use multivitamins, the uncertainty regarding their efficacy and safety is striking. Clearly, rigorous studies are needed to provide this information. The panel went a step further, saying that "It is important that the FDA’s purview over these products be authorized and implemented."

— Richard Saitz, MD, MPH, FACP, FASAM

Published in Journal Watch September 28, 2006

Citation(s):

NIH State-of-the-Science Panel. National Institutes of Health state-of-the-science conference statement: Multivitamin/mineral supplements and chronic disease prevention. Ann Intern Med 2006 Sep 5; 145:364-71.