For decades, colorful multivitamin bottles have lined pharmacy shelves and kitchen cabinets, promising better health to millions. But how much do these supplements actually help us live longer?
An analysis led by Dr. Neal D. Barnard and colleagues at the George Washington University School of Medicine & Health Sciences, delivers a surprising answer: not only do multivitamins fail to reduce the risk of death, but there’s even evidence they could do more harm than good—at least for some.
Drawing on data from more than 390,000 participants tracked over 20 years across three large U.S. cohorts, Barnard and team set out to test whether multivitamin use is associated with improved longevity. The results were striking. Multivitamin use did not lower mortality at all. In fact, in the early years of the studies, multivitamin users faced a 4% higher mortality risk compared to nonusers (adjusted hazard ratio 1.04; 95% CI 1.02–1.07). This echoed the findings of numerous earlier trials and observational studies. Despite hopes and hype, these vitamin-packed capsules – often touted as a daily insurance policy against poor diets – do not appear to buy anyone more years of life.
The allure of multivitamins isn’t new. The concept of vitamins as essential dietary components has its roots deep in history, from sailors preventing scurvy with citrus fruits to landmark experiments with thiamine-rich brown rice curing beri-beri. By the early 20th century, scientists like Casimir Funk had coined the term “vitamines,” recognizing vital roles for these microscopic nutrients. Today, with one in three American adults taking multivitamin supplements, understanding their true value is of crucial public health importance.
Barnard’s work, which builds on a 2007 National Institutes of Health consensus definition for multivitamin supplements—products containing at least three vitamins and minerals below recommended safety limits and containing no herbal or pharmacological agents—synthesizes more than two decades of rigorous mortality data. Yet, the study’s message is clear: for most adults, multivitamins simply don’t deliver on longevity promises.
There are some exceptions. The analysis notes specific cases in which targeted supplementation is beneficial: women of childbearing age taking folate to prevent neural tube defects, or certain nutrients like B12 and D provided after bariatric surgery or, in aging adults, to protect cognition and vision. In rare instances, such as the progression of macular degeneration, vitamins C, E, zinc, and beta carotene may help delay vision loss. But for the general population, piling on multivitamins seems unnecessary—and potentially risky.
Indeed, certain supplements, when taken alongside medications or in excess, have documented downsides. Supplemental beta carotene has been shown to increase lung cancer risk among smokers and asbestos workers, while added iron could raise the risk of cardiovascular disease, diabetes, or dementia in some populations. Other minerals might interfere with antibiotics, and the vitamin E found in pills doesn’t fully match the diversity found in whole foods. The conclusion is sobering: food sources of vitamins and minerals remain vastly superior, and over-reliance on pills may inadvertently increase certain health risks.
As Barnard and his team point out, the evidence supporting multivitamins as a magic bullet continues to unravel. For most, the path to a longer life is lined not with pills, but with plant foods and balanced nutrition. When supplementation is truly necessary, it’s best tailored to individual risk and need—not one-size-fits-all capsules.
References:
Study:
Barnard ND, Kahleova H, Becker R. (2024). The Limited Value of Multivitamin Supplements. JAMA Network Open. 7(6):e2418965. doi:10.1001/jamanetworkopen.2024.18965
Further reading:
National Institutes of Health State-of-the-Science Conference Statement: multivitamin/mineral supplements and chronic disease prevention. Am J Clin Nutr. 2007;85(1):257S-264S. doi:10.1093/ajcn/85.1.257S
Loftfield E, O’Connell CP, Abnet CC, et al. Multivitamin use and mortality risk in 3 prospective US cohorts. JAMA Netw Open. 2024;7(6):e2418729. doi:10.1001/jamanetworkopen.2024.18729
Vyas CM, Manson JE, Sesso HD, et al. Effect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS. Am J Clin Nutr. 2024;119(3):692-701. doi:10.1016/j.ajcnut.2023.12.011
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