Multivitamin: a daily base, honestly explained
The multivitamin is the world's most common supplement — and one of the most oversold. Here's the honest version: what it can do, what it can't, and who actually benefits.
Start with the food
No supplement replaces a varied diet, and a multivitamin is not a license to eat worse. The honest starting point: if you eat a broad, mostly whole-food diet, you're probably covering most bases already. A multivitamin is a base layer — insurance for the days and seasons that aren't ideal — not a shortcut.
What the research shows
- On the big outcomes — heart disease, cancer, dying earlier — the evidence review behind the US Preventive Services Task Force's 2022 statement concluded there is insufficient evidence that a multivitamin protects healthy adults. Anyone selling a multivitamin as disease prevention is ahead of the science.
- The most interesting recent signal is cognition in older adults: in the large randomised COSMOS-Mind trial, three years of a daily multivitamin modestly improved memory and global cognition versus placebo. Promising, replicated within the same study program — but still a young finding, not a settled claim.
- What is settled sits at the nutrient level: EU-authorised claims exist for the individual vitamins and minerals inside — vitamin D and normal immune function, B12 and folate and reduction of tiredness and fatigue, and many more in the EU register. There is no authorised claim for "multivitamin" as a category.
Who actually benefits
- People with restricted diets — vegans and vegetarians (B12 especially), low-calorie dieters, picky eaters.
- Older adults, where appetite and absorption both drift down.
- Dark-season Nordics — vitamin D from October to March is the classic gap (we've written about the Nordic winter).
- People in demanding stretches where food quality realistically slips.
What to look for
Moderate doses. A good multivitamin covers around 100 % of the reference intake across the board — not 1,000 %. Megadoses aren't better; for some nutrients (vitamin A, iron for men) more is worse. One a day, with food, is the whole routine.
In short
A multivitamin won't extend your life, and the science is honest about that. What it does is simpler: it quietly closes the everyday gaps a real life leaves open — and for the brain in older age, the early evidence is genuinely interesting. Food first, base layer second. Do your daily.
Sources
- O'Connor et al. (2022). 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.
- Baker et al. (2023). Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial (COSMOS-Mind). Alzheimer's & Dementia.
- EU register of authorised health claims — per-nutrient claims (vitamin D, B12, folate and others).