http://dx.doi.org/10.7326/0003-4819-159-12-201312170-00011 http://dx.doi.org/10.7326/0003-4819-159-12-201312170-00011 Three articles in this issue address the

http://dx.doi.org/10.7326/0003-4819-159-12-201312170-00011 http://dx.doi.org/10.7326/0003-4819-159-12-201312170-00011 Three articles in this issue address the role of vitamin and mineral supplements for preventing the occurrence or progression of chronic diseases. First, Fortmann and colleagues systematically reviewed trial evidence to update the U.S. Preventive Services Task Force recommendation on the efficacy of vitamin supplements for primary prevention in community-dwelling adults with no nutritional deficiencies. After reviewing 3 trials of multivitamin supplements and 24 trials of single or paired vitamins that randomly assigned more than 400 000 participants, the authors concluded that there was no clear evidence of a beneficial effect of supplements on all-cause mortality, cardiovascular disease, or cancer. Second, Grodstein and coworkers evaluated the efficacy of a daily multivitamin to prevent cognitive decline among 5947 men aged 65 years or older participating in the Physicians’ Health Study II. After 12 years of follow-up, there were no differences between the multivitamin and placebo groups in overall cognitive performance or verbal memory. Adherence to the intervention was high, and the large sample size resulted in precise estimates showing that use of a multivitamin supplement in a well-nourished elderly population did not prevent cognitive decline. Grodstein and coworkers’ findings are compatible with a recent review (3) of 12 fair- to good-quality trials that evaluated dietary supplements, including multivitamins, B vitamins, vitamins E and C, and omega-3 fatty acids, in persons with mild cognitive impairment or mild to moderate dementia. None of the supplements improved cognitive function. Third, Lamas and associates assessed the potential benefits of a high-dose, 28-component multivitamin supplement in 1708 men and women with a previous myocardial infarction participating in TACT (Trial to Assess Chelation Therapy). After a median follow-up of 4.6 years, there was no significant difference in recurrent cardiovascular events with multivitamins compared with placebo (hazard ratio, 0.89 [95% CI, 0.75 to 1.07]). The trial was limited by high rates of nonadherence and dropouts. The large body of accumulated evidence has important public health and clinical implications. Evidence is sufficient to advise against routine supplementation, and we should translate null and negative findings into action. The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided. This message is especially true for the general population with no clear evidence of micronutrient deficiencies, who represent most supplement users in the United States and in other countries.