Don’t take multivitamins for longevity or heart protection

Over 14000 male doctors took multivitamins for eleven years. The number of serious heart and vascular problems, as well as deaths, was virtually identical between those who took them and those who didn’t. When nine separate clinical trials were pooled together, there was no measurable effect on mortality at all. Skipping them saves you between 200 and 700 yuan each year. This does not apply to people who have been medically diagnosed with specific nutrient deficiencies, nor to pregnant women needing folic acid.

They cost roughly 0.5 to 2 yuan per day, or 200 to 700 yuan per year. Taking them requires almost no time — just one pill a day. Over time, they can create a sense of dependency, making it feel like something is missing if you skip a day.

The PHS II trial enrolled 14641 male doctors and followed them for a median period of 11.2 years (some longer, some shorter). The rate of major cardiovascular events was identical between the groups; the hazard ratio was 1.01 (95% CI 0.91–1.10), meaning no real difference. Similarly, overall mortality showed no difference, with a hazard ratio of 0.94 (95% CI 0.88–1.02). The USPSTF evaluated nine randomized controlled trials with 51550 participants and concluded there is insufficient evidence to support any link between multivitamins and reduced mortality; it assigned a Grade I rating. The perception that they are worthwhile stems largely from the idea of “one pill covering all nutrients” and their extremely low cost.

A point of debate: among the same group of male doctors, cancer rates were examined as well. Those taking multivitamins showed an 8% lower incidence of cancer (95% CI 0.86–0.998, P=0.04), which just barely crosses the threshold for statistical significance. Cancer-related mortality was also 12% lower (95% CI 0.77–1.01), but this range includes 1, so it may well be a random fluctuation. Any such benefit appears very small and applies only to male doctors. It does not apply to individuals with diagnosed nutrient deficiencies, pregnant women, or those with highly unbalanced diets who require targeted supplementation as advised by medical professionals.

Sesso HD et al. (2012). Multivitamins in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial. JAMA. https://doi.org/10.1001/jama.2012.14805；US Preventive Services Task Force (2022). Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer. JAMA. https://doi.org/10.1001/jama.2022.8970；Gaziano JM 等 (2012). Multivitamins in the Prevention of Cancer in Men. JAMA. https://doi.org/10.1001/jama.2012.14641（备注里那项癌症结果）