Multivitamin
Daily multi / one-a-day · Foundation
Cheap insurance against gaps, repeatedly unable to prove it does anything beyond that.
What the evidence says
Pooled trials found no effect on mortality and a small reduction in cancer incidence; the US Preventive Services Task Force issued an insufficient-evidence finding rather than a conclusion that benefit was disproved. Three COSMOS cognitive substudies produced a pooled modest signal in older adults — related substudies rather than independent replication. Where a genuine dietary gap exists, filling it helps; the product cannot tell you whether you have one.
What studies used
One daily dose of a formulation at or near recommended intakes. Fat-soluble vitamins absorb better with a meal.
Reported from published studies and product labelling — a record of what was used in research, not a recommendation. What is right for you is a conversation with a clinician.
Watch out for
- A multi plus individual supplements is the usual route to exceeding upper limits on the fat-soluble vitamins and on selenium, zinc and iron
- Iron-containing multis are a poor default for men and post-menopausal women
Evidence base
established literature
Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.
This letter measures how much human research exists, not whether it works for you — the tier above (Limited) is the read on quality.
Research (12)
- Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical TrialAm J Clin Nutr · 2023
- 2020
- Guideline No. 427: Folic Acid and Multivitamin Supplementation for Prevention of Folic Acid-Sensitive Congenital AnomaliesJ Obstet Gynaecol Can · 2022
- Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: US Preventive Services Task Force Recommendation StatementJAMA · 2022
- Multivitamin/mineral supplements: Rationale and safetyNutrition · 2017
- Multivitamin/mineral supplements: Rationale and safety - A systematic reviewNutrition · 2017
- Multivitamin-multimineral supplementation and mortality: a meta-analysis of randomized controlled trialsAm J Clin Nutr · 2013
- Search for the most complete multivitaminAsia Pac J Clin Nutr · 2004
- Parenteral Nutrition Multivitamin Product Shortage ConsiderationsNutr Clin Pract · 2016
- Multivitamin use and adverse birth outcomes in high-income countries: a systematic review and meta-analysisAm J Obstet Gynecol · 2017
- Multivitamin-multimineral supplements and eye disease: age-related macular degeneration and cataractAm J Clin Nutr · 2007
- Prenatal multivitamin supplementation and rates of congenital anomalies: a meta-analysisJ Obstet Gynaecol Can · 2006
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