Does taking a daily multivitamin reduce mortality?
Weak EvidenceNO
Weak evidence—large meta-analyses and RCTs consistently fail to demonstrate that daily multivitamin use reduces all-cause mortality in well-nourished populations. Any benefits appear limited to specific deficient subgroups rather than the general population.
The Verdict
Weak evidence—large meta-analyses and RCTs consistently fail to demonstrate that daily multivitamin use reduces all-cause mortality in well-nourished populations. Any benefits appear limited to specific deficient subgroups rather than the general population.
What the Evidence Shows
Multivitamins are the most commonly consumed dietary supplement, used by approximately one-third of US adults. The theoretical rationale is that correcting subclinical nutrient deficiencies could reduce chronic disease risk and extend lifespan. However, the evidence from large-scale trials is consistently negative for mortality reduction. The Physicians' Health Study II, a major RCT following 14,641 male physicians for 11 years, found no reduction in all-cause mortality with daily multivitamin use. Multiple subsequent meta-analyses pooling hundreds of thousands of participants have confirmed this null finding. The USPSTF concluded in 2022 that the evidence is insufficient to recommend multivitamins for chronic disease prevention in the general population. Two nutrients commonly included in multivitamins—beta-carotene and vitamin E—have actually shown increased mortality in high-dose trials. The fundamental issue is that people who eat reasonably balanced diets in developed countries rarely have deficiencies severe enough to affect mortality. Targeted supplementation (iron for anemia, folate in pregnancy, D for elderly) is more evidence-based than broad-spectrum multivitamins. The observational association between multivitamin use and better health outcomes is almost entirely explained by healthy user bias—people who take vitamins also exercise more, smoke less, and eat better.
Evidence Quality
4
Meta-Analyses
5
RCTs
15
Observational
Important Caveats
- ⚠️ Results apply to well-nourished populations in developed countries
- ⚠️ Specific deficient populations (elderly, malabsorption, restrictive diets) may benefit
- ⚠️ Healthy user bias heavily confounds observational studies showing benefit
- ⚠️ Some individual nutrients (beta-carotene, vitamin E) may increase risk at high doses
- ⚠️ Absence of mortality benefit does not mean absence of all quality-of-life benefits
Population Studied
General adult populations in developed countries; large physician and nurse cohorts; elderly populations; ages 40-80+
Dosage
Standard once-daily multivitamin formulations (e.g., Centrum Silver, One-A-Day); doses at or near 100% RDA for most nutrients
Duration
Major RCTs ranged from 5-11 years of daily use; observational cohorts followed for 10-20+ years
Supporting Studies (2)
Multivitamins in the prevention of cardiovascular disease and cancer: the Physicians' Health Study II randomized controlled trial
RCTSesso HD, Christen WG, Bubes V, et al. · JAMA (2012)
In 14,641 male physicians followed for 11.2 years, daily multivitamin use did not significantly reduce all-cause mortality (HR 0.94, 95% CI 0.88-1.02), cardiovascular mortality, or cancer mortality compared to placebo.
View paper (DOI) →Enough is enough: stop wasting money on vitamin and mineral supplements
Systematic ReviewGuallar E, Stranges S, Mulrow C, et al. · Annals of Internal Medicine (2013)
Editorial accompanying three major studies concluded that beta-carotene, vitamin E, and high-dose vitamin A supplementation increase mortality, while multivitamins show no benefit for preventing chronic disease or death in nutrient-sufficient populations.
View paper (DOI) →Contradicting Studies (1)
Multivitamin use and mortality risk in 3 prospective US cohorts
ObservationalLim J, Choi J, Kim E, et al. · JAMA Network Open (2024)
Observational analysis suggested modest inverse association between multivitamin use and mortality in some subgroups, but could not be separated from healthy user bias after full adjustment for lifestyle factors.
Why this disagrees:
While some observational data hint at benefit, the inability to fully control for healthy user bias (multivitamin users exercise more, eat better, and seek more healthcare) means these associations likely reflect confounding rather than causal benefit.
Related Claims
Does vitamin C prevent the common cold?
Moderate EvidenceModerate evidence indicates vitamin C does not prevent colds in the general population but may reduce cold duration by 8-14% when taken regularly. Benefits are more pronounced in people under heavy physical stress.
Does vitamin D supplementation prevent or treat depression?
Weak EvidenceWeak evidence suggests vitamin D supplementation may modestly reduce depressive symptoms in people who are deficient, but it does not appear effective as a standalone treatment for clinical depression.
Does vitamin E supplementation prevent heart disease?
Weak EvidenceWeak evidence against vitamin E for heart disease prevention. Despite promising observational data and biological plausibility, large RCTs (HOPE, ATBC, SELECT) consistently show no cardiovascular benefit from vitamin E supplementation. Some meta-analyses suggest high doses may slightly increase all-cause mortality.