Multivitamin (multivitamin/mineral)
Summary
In the largest trials, a daily multivitamin did not lower heart attacks, strokes or overall deaths. Total cancer was 8% lower in one 11-year trial of male doctors but not in a later trial, and memory scores were slightly better in older adults (grade C). Products vary widely, and the vitamin K content matters for people on warfarin.
Key facts
- No effect on major cardiovascular events in 14,641 male physicians over 11.2 years (HR 1.01)[2]
- Total cancer 8% lower over 11.2 years in men (HR 0.92); no effect over 3.6 years in 21,442 older adults (HR 0.97)[1][4]
- Pooled COSMOS substudies (5,203 older adults): small gains in global cognition and episodic memory[7]
- ODS names vitamin K in multivitamins as the one important medicine interaction[10]
- Both big trials tested Centrum Silver supplied by its maker; COSMOS was also funded by a Mars Edge grant[1][4]
- 7 graded human outcomes on this page
- October 13, 2026
How it works
ProposedA multivitamin raises intakes of nutrients a diet may lack; ODS notes it also makes intakes above the upper limit more likely when combined with fortified foods and single-nutrient supplements. Why it might modestly affect cancer or memory in trials is not established.[10]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Cancer | Grade C | Mixed | Systematic review of 4 trials · n = 48,859 · 2022 | 3 rows |
| Eyes | Grade C | Mixed | RCT · n = 14,641 · 2014 | 1 row |
| Memory | Grade C | Improved | Meta-analysis of 3 trials · n = 5,203 · 2024 | 2 rows |
| Heart | No effect | No effect | RCT · n = 14,641 · 2012 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Cancer in adults without known deficiency (pooled multivitamin trials) | Mixed | Grade C | Systematic review · n = 48,859 · 2022 Adults in 4 multivitamin RCTs Form: Multivitamins (various products) · Dose: As used in each trial · Duration: Varied Multivitamin use was linked to slightly lower any-cancer incidence (OR 0.93, 95% CI 0.87–0.99) and lung cancer (OR 0.75, 2 trials); the review noted important limitations. Beta-carotene raised lung cancer risk (OR 1.20). | 35727272 (opens PubMed)Source [8] |
| Total cancer incidence | Mixed | Grade C | RCT · n = 14,641 · 2012 US male physicians aged 50+ Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: Median 11.2 years Total cancer 17.0 vs 18.3 events per 1,000 person-years (HR 0.92, 95% CI 0.86–0.998); no significant effect on prostate, colorectal or other site-specific cancers. | 23162860 (opens PubMed)Source [1] |
| Cataract and age-related macular degeneration | Mixed | Grade C | RCT · n = 14,641 · 2014 US male physicians aged 50+ Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: Mean 11.2 years Cataract 872 vs 945 cases (HR 0.91, 95% CI 0.83–0.99); visually significant macular degeneration 152 vs 129 cases (HR 1.19, not significant). | 24268861 (opens PubMed)Source [3] |
| Global cognition and episodic memory | Improved | Grade C | Meta-analysis · n = 5,203 · 2024 US adults aged 60+ in three COSMOS substudies (Clinic, Mind, Web) Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: 2–3 years Global cognition +0.07 SD units (95% CI 0.03–0.11) and episodic memory +0.06 SD units versus placebo; the authors equated the global effect to about 2 years less cognitive aging. | 38244989 (opens PubMed)Source [7] |
| Immediate word recall (episodic memory) | Improved | Grade C | RCT · n = 3,562 · 2023 Older US adults in COSMOS-Web (online testing) Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: 3 years Better immediate word recall than placebo at 1 year (the primary endpoint) and on average over 3 years; no significant effects on secondary outcomes. | 37244291 (opens PubMed)Source [6] |
| Total invasive cancer | No effect | No effect | RCT · n = 21,442 · 2022 US women 65+ and men 60+ Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: Median 3.6 years Invasive cancer in 518 vs 535 participants (HR 0.97, 95% CI 0.86–1.09); lung cancer lower (HR 0.62); no effect on cardiovascular events (HR 0.98) or all-cause mortality (HR 0.93). No safety concerns. | 35294969 (opens PubMed)Source [4] |
| Major cardiovascular events (heart attack, stroke, CVD death) | No effect | No effect | RCT · n = 14,641 · 2012 US male physicians aged 50+ Form: Centrum Silver daily multivitamin · Dose: 1 tablet/day · Duration: Median 11.2 years Major cardiovascular events 11.0 vs 10.8 per 1,000 person-years (HR 1.01, 95% CI 0.91–1.10); no effect on heart attack, stroke, CVD death or total mortality (HR 0.94, not significant). | 23117775 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Basic once-daily multivitamin/mineral | Varies[10] | ODS describes basic products as containing most vitamins and minerals at or below daily-value amounts.[10] | ODS reports no adverse effects in studies of users beyond minor gastrointestinal complaints in both supplement and placebo groups.[10] | General nutrient intake; the large trials used this kind of product |
| High-potency or specialty multivitamins | Varies[10] | Some provide nutrients well above the daily value or even the upper limit, often in multi-pill packs.[10] | Higher risk of exceeding upper limits, especially combined with fortified foods and single supplements.[10] | Not tested in the outcome trials cited here |
| Formulas for adults 50+ (for example, Centrum Silver) | Varies[10] | ODS notes senior formulas usually contain little or no iron and more calcium, vitamin D and vitamin B12.[10] | Used in PHS II and COSMOS; COSMOS reported no safety concerns.[1][4] | Cancer, cardiovascular, eye and memory outcomes in PHS II and COSMOS |
Studied doses
Doses studied in human trials ranged from one tablet a day of a standard multivitamin/mineral for about 2–3 years (COSMOS substudies) to the same daily tablet for a median of 11.2 years (Physicians' Health Study II).[1][4][7]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Warfarin and similar blood thinnersNIH fact sheetVitamin K in a multivitamin can reduce warfarin's effect; ODS calls this the one important interaction for multivitamins with nutrients in recommended amounts.[10]
Other supplements
- Other supplements and fortified foodsNIH fact sheetStacking these with a multivitamin raises the chance of going over upper limits for some nutrients.[10]
Who should be careful
- People taking warfarin
- Check the vitamin K content and keep intake consistent; ODS advises talking with a clinician before starting a vitamin K-containing multivitamin.[10]
- Current or former smokers
- Avoid products with large amounts of beta-carotene or vitamin A: ODS notes two trials linked these to more lung cancer in smokers, and the USPSTF recommends against beta-carotene supplements for heart and cancer outcomes.[8][10][11]
- Pregnancy
- Too much preformed vitamin A (retinol) in pregnancy can cause birth defects (UL 3,000 mcg/day for adult women); prenatal formulas are designed for this stage.[10]
- People already using several supplements
- Combining a multivitamin with single-nutrient products and fortified foods can push some intakes above the upper limit.[10]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Beta-carotene, vitamin A and smoking
Frequently asked questions
Does a daily multivitamin help the heart?
Not in the largest trials: neither the 11-year Physicians' Health Study II nor COSMOS found fewer heart attacks, strokes or cardiovascular deaths.[2][4]
Do multivitamins lower cancer risk?
Total cancer was 8% lower in one 11-year trial of male doctors, but a 3.6-year trial in older men and women found no effect. The USPSTF found the evidence insufficient.[1][4][11]
Can a multivitamin improve memory?
In older adults, pooled COSMOS substudies found small improvements in global cognition and episodic memory with Centrum Silver over 2–3 years.[7]
Is a multivitamin safe with warfarin?
Vitamin K in many multivitamins can weaken warfarin's effect, so ODS advises discussing it with a clinician first.[10]
Sources
- [1]Multivitamins in the prevention of cancer in men: the Physicians' Health Study II randomized controlled trial.. JAMA, 2012. RCT
- [2]Multivitamins in the prevention of cardiovascular disease in men: the Physicians' Health Study II randomized controlled trial.. JAMA, 2012. RCT
- [3]Effects of multivitamin supplement on cataract and age-related macular degeneration in a randomized trial of male physicians.. Ophthalmology, 2014. RCT
- [4]Multivitamins in the prevention of cancer and cardiovascular disease: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial.. Am J Clin Nutr, 2022. RCT
- [5]Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial.. Alzheimers Dement, 2023. RCT
- [6]Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial.. Am J Clin Nutr, 2023. RCT
- [7]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. meta-analysis
- [8]Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.. JAMA, 2022. systematic-review
- [9]Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts.. JAMA Netw Open, 2024. observational
- [10]Multivitamin/mineral Supplements: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, 2024. fact-sheet
- [11]Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation Statement.. JAMA, 2022. guideline
What changed
- Editorial evidence re-review: smoker warning now states the USPSTF recommendation accurately (against beta-carotene supplements generally, PMID 35727271); cohort insight now reports that mortality was slightly higher, not just not lower. Trial numbers and sponsor disclosures (BASF/Pfizer/DSM for PHS II; Mars Edge and Pfizer for COSMOS) re-checked in full text.
- Second-pass self-review: every PMID re-checked against NCBI esummary (title, year, no retraction or expression-of-concern flag), every dose, n and duration re-read against the PubMed abstract or PMC full text, grades held conservative, and interactions limited to what a cited source supports.
- First draft. Source titles and years taken from NCBI E-utilities esummary; abstracts read for every evidence row.