No Vitamins Are Proven to Extend Lifespan in Healthy Adults
Based on the highest-quality evidence from the U.S. Preventive Services Task Force, vitamin supplementation does not reduce mortality or prevent major diseases in generally healthy adults. The USPSTF systematically reviewed 24 studies of individual vitamins and found no evidence of beneficial effect on cardiovascular disease, cancer, or all-cause mortality 1.
Evidence Against Common "Longevity" Vitamins
Vitamins With No Mortality Benefit
Vitamin A: No effect on all-cause mortality. In high-risk populations (smokers, asbestos workers), it actually increased lung cancer risk and related deaths. One cohort study showed increased hip fractures in postmenopausal women 1.
Vitamin C: Two RCTs found no statistically significant effect on cardiovascular disease, cancer, or all-cause mortality 1.
Vitamin E: Five trials reporting mortality outcomes showed no effect on all-cause mortality. One trial found increased risk for hemorrhagic stroke. Mixed results for prostate cancer, with SELECT showing increased risk after extended follow-up 1.
β-Carotene: Six clinical trials consistently showed no decrease in cardiovascular disease, cancer incidence, or cancer mortality. Two major trials (ATBC and CARET) demonstrated increased lung cancer incidence, mortality, and all-cause mortality in high-risk populations 1.
Vitamin D: Limited Benefit Only in Adults ≥75 Years
The 2024 Endocrine Society guideline provides the only evidence-based recommendation for vitamin supplementation and longevity 2:
- For adults 75+ years: Empiric vitamin D supplementation may lower mortality risk (RR 0.96,95% CI 0.93-1.00), translating to 6 fewer deaths per 1000 people 2.
- Dosing: Approximately 900 IU (23 μg) daily based on weighted average from trials. Daily, lower-dose preferred over intermittent high doses 2.
- No routine testing recommended: 25(OH)D thresholds for outcome-specific benefits have not been established in clinical trials 2.
- For adults under 75: No mortality benefit demonstrated.
Multivitamins: Inconsistent and Non-Generalizable
The SU.VI.MAX study showed a 31% reduction in cancer incidence in men but no effect in women, making extrapolation to the general population difficult due to different supplement formulations and sex-specific responses 1.
Critical Caveats
Potential harms exist: Several vitamins showed increased risks in specific populations:
- Vitamin A/β-carotene: Increased lung cancer in smokers
- Vitamin E: Increased hemorrhagic stroke risk
- High-dose vitamin A: Increased hip fractures in postmenopausal women
The "longevity vitamin" concept lacks clinical validation: While theoretical frameworks propose compounds like ergothioneine, PQQ, lutein, and carotenoids as "longevity vitamins" 3, these remain hypothetical constructs without RCT evidence demonstrating mortality reduction in humans.
Recent observational studies are misleading: A 2026 NHANES analysis suggested vitamin C and B2 associations with biological aging markers 4, but these are cross-sectional observations that cannot establish causation and directly contradict the RCT evidence showing no mortality benefit 1.
Bottom Line Algorithm
Age <75 years: Do not supplement vitamins for longevity purposes. Focus on correcting documented deficiencies only.
Age ≥75 years: Consider vitamin D 800-1000 IU daily without routine testing, as this is the only vitamin with guideline-level evidence for mortality reduction 2.
High-risk populations (smokers, asbestos exposure): Avoid vitamin A and β-carotene supplementation due to increased cancer risk 1.
All ages: Prioritize obtaining nutrients from whole foods rather than supplements, as the evidence consistently fails to show benefit from isolated vitamin supplementation in healthy individuals.
The evidence is clear: vitamin supplementation does not extend lifespan in generally healthy adults under 75 years, and some vitamins may cause harm in specific populations.