Multivitamins feel like insurance. The data found no payout.

Cohort study. 390,124 people. 23.5 years median follow-up (up to 27 years).

People were watched for years. Nobody was told what to do. A clue, not proof.

Who: Generally healthy US adults without a history of cancer, diabetes, heart attack, stroke or kidney failure at baseline, from NIH-AARP (327,732), PLCO (42,732) and the Agricultural Health Study (19,660); median age 61.5, 55.4% male, mostly White; multivitamin use assessed 1993-2001

• Lower death risknone
• Fewer heart, cancer, stroke deathsnone
• Daily users' habitshealthier

More to know, from our read of the paper:

• Observational: association, not causation; authors say residual confounding by poorly measured or unmeasured factors (eg, health care utilization) may bias estimates
• Multivitamin use was self-reported via questionnaires (at baseline, plus one follow-up in the time-varying analysis)
• Healthy-user effect: daily users were more often female and college educated, smoked less, ate better and had lower BMI; the paper adjusted for these but cannot rule out bias
• Mostly White participants; exclusions for missing data mean generalizability to the total US population may be limited
• Multivitamin composition/dose was not analysed; authors say differing MV composition may explain varying results across studies

390,124 generally healthy US adults reported whether they took multivitamins and were followed for a median of 23.5 years. Daily users were not less likely to die, and not less likely to die of heart disease, cancer or stroke. Daily users smoked less and ate better, and after adjusting for that they even had a slightly higher (4%) risk of death over the first 12 years. Observational: linked, not proven. People with deficiencies weren't studied, and only death was measured.

We read the abstract and the full text of this paper and checked every number on this page against it (16 facts, checked on 2026-09-27). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.