January 8, 2014
TAKE A PEZ INSTEAD:
Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements (Eliseo Guallar, MD, DrPH; Saverio Stranges, MD, PhD; Cynthia Mulrow, MD, MSc, Senior Deputy Editor; Lawrence J. Appel, MD, MPH; and Edgar R. Miller III, MD, PhD, Ann Intern Med. 2013)
Posted by Orrin Judd at January 8, 2014 4:48 PMThe 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.The evidence also has implications for research. Antioxidants, folic acid, and B vitamins are harmful or ineffective for chronic disease prevention, and further large prevention trials are no longer justified. Vitamin D supplementation, however, is an open area of investigation, particularly in deficient persons. Clinical trials have been equivocal and sometimes contradictory. For example, supplemental vitamin D, which might prevent falls in older persons, reduced the risk for falls in a few trials, had no effect in most trials, and increased falls in 1 trial. Although future studies are needed to clarify the appropriate use of vitamin D supplementation, current widespread use is not based on solid evidence that benefits outweigh harms.With respect to multivitamins, the studies published in this issue and previous trials indicate no substantial health benefit. This evidence, combined with biological considerations, suggests that any effect, either beneficial or harmful, is probably small. As we learned from voluminous trial data on vitamin E, however, clinical trials are not well-suited to identify very small effects, and future trials of multivitamins for chronic disease prevention in well-nourished populations are likely to be futile.In conclusion, β-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful. Other antioxidants, folic acid and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases. Although available evidence does not rule out small benefits or harms or large benefits or harms in a small subgroup of the population, we believe that the case is closed-- supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough.