Are Daily Multivitamins Worth Taking? What the Evidence Shows

Are Daily Multivitamins Worth Taking? What the Evidence Shows

The short answer: for most reasonably well-nourished adults in the UK, a standard daily multivitamin is unlikely to dramatically extend lifespan or prevent major chronic diseases — but for specific groups (older adults, pregnant women, those on restrictive diets, people with diagnosed deficiencies), the evidence is strong enough that the NHS itself recommends supplementation. The real question is not whether multivitamins are universally "good" or "bad", but whether the formulation, dosage, and consumer expectation match the actual evidence. If you want a broader foundation first, read the main complete guide to why you should take supplements before deciding where multivitamins fit into your routine.

This article cuts through the marketing noise and looks at what peer-reviewed research, NHS guidance, and UK regulatory bodies actually say. It will help you decide whether a daily multivitamin is a sensible, evidence-based purchase — or money better spent elsewhere.

What the Major Studies Actually Found

The most important data on multivitamins comes from three large, long-running trials and several meta-analyses. Understanding their scope — and their limitations — is essential before spending any money.

The Physicians' Health Study II (2012)

Published in JAMA in 2012, this US trial followed 14,641 male doctors aged 50 and over for around 11 years. Roughly half took a daily Centrum Silver multivitamin, the other half a placebo. The headline finding: no statistically significant reduction in major cardiovascular events, heart attack, stroke, or all-cause mortality. However, the trial did find a modest but statistically significant 8% reduction in total cancer incidence in the multivitamin group.

Crucially, this was a well-nourished population of doctors. They were eating reasonably balanced diets, exercising more than average, and earning enough to afford quality food. A daily multivitamin was, in effect, added on top of an already healthy lifestyle — which is precisely the population in which you would expect the smallest marginal benefit.

The COSMOS Trial (2022 and 2024 follow-ups)

The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is the largest and most rigorous modern multivitamin trial to date. It enrolled over 21,000 participants in the US (mean age 72) and used a Centrum Silver formulation. The 2022 results in Alzheimer's & Dementia showed that after three years, participants taking the multivitamin had a statistically significant improvement in episodic memory — equivalent to roughly three years of age-related memory decline reversed. A 2024 follow-up replicated the cognitive benefit but found no effect on cardiovascular events.

For older adults concerned about cognitive ageing — a major concern in a UK population where dementia affects nearly one million people — this is the strongest evidence yet that a daily multivitamin can deliver a measurable, clinically relevant benefit.

2024 Meta-Analysis: 1.5 Million Participants

A 2024 meta-analysis in JAMA Network Open pooled data from over 1.5 million participants across multiple large trials. The conclusions were clear: multivitamins do not reduce all-cause mortality, cardiovascular mortality, or cancer mortality. They do, however, consistently improve serum levels of key micronutrients — particularly vitamin D, vitamin B12, and folate — in people who started out with low or marginal status.

This distinction is critical. Multivitamins are not magic. They correct deficiencies. If you are not deficient in the first place, the marginal benefit on hard disease endpoints is small. If you are deficient, the benefit can be substantial.

Who Actually Benefits: The NHS-Recognised Groups

Rather than relying on supplement industry marketing, it is far more reliable to follow the official guidance from bodies such as the NHS, the Scientific Advisory Committee on Nutrition (SACN), and Public Health England (now the Office for Health Improvement and Disparities).

Pregnant Women and Those Trying to Conceive

The NHS recommends 400 micrograms of folic acid daily for anyone trying to conceive, increasing to 5 milligrams per day for those with a higher risk of neural tube defects (such as a previous affected pregnancy or diabetes). Folic acid is a synthetic form of folate, and supplementing in the first 12 weeks of pregnancy reduces the risk of neural tube defects such as spina bifida by around 70%.

Standard daily multivitamins marketed for pregnancy (e.g. Pregnacare, Boots Pharmaceuticals Pregnancy Support) typically contain the recommended 400-microgram dose, alongside 10 micrograms of vitamin D, which the NHS also advises during pregnancy and breastfeeding. The NICE guideline NG62 sets out the full framework.

Adults Aged 65 and Over

The COSMOS findings align with what smaller UK studies have shown for years: older adults are at higher risk of marginal deficiencies in vitamin D, B12, calcium and magnesium, particularly if they eat less, have reduced appetite, or take medications that interfere with absorption (such as metformin or proton pump inhibitors). A daily multivitamin-mineral supplement designed for over-50s is a reasonable, low-risk intervention.

Children Aged 6 Months to 5 Years

The NHS recommends vitamin A, C and D supplementation for all children in this age group, unless they are drinking more than 500ml of formula milk per day. Public Health England's "Healthy Start" programme provides free vitamins to eligible low-income families, including drops for children and tablets for pregnant and breastfeeding women.

People on Restricted or Plant-Based Diets

Vegans and vegetarians are at higher risk of deficiencies in vitamin B12, iron, zinc, iodine, calcium, and long-chain omega-3 fatty acids (EPA and DHA). A standard multivitamin will not cover all of these — B12 and iodine typically need separate targeted supplementation, and omega-3s require an algae-based product. However, a daily multivitamin remains a sensible foundation for anyone moving to a fully plant-based diet.

People with Darker Skin or Limited Sun Exposure

The NHS recommends 10 micrograms of vitamin D daily for all UK adults during autumn and winter, and year-round for those with darker skin, those who cover their skin for cultural reasons, and people who are housebound or rarely go outdoors. Most standard multivitamins contain 5 to 10 micrograms of vitamin D, which is enough to meet this baseline recommendation but is not therapeutic for an established deficiency.

What Is Actually in a UK Daily Multivitamin?

The UK market is large and lightly regulated. The Medicines and Healthcare products Regulatory Agency (MHRA) classifies most vitamin and mineral products as food supplements rather than medicines, which means they are not subject to the same efficacy and safety testing as licensed medicines. The Food Standards Agency (FSA) oversees this market, including labelling under the Food Supplements (England) Regulations 2003.

A typical supermarket own-brand daily multivitamin in the UK (e.g. Boots Pharmaceuticals A-Z, Tesco Health A-Z, or LloydsPharmacy Everyday Health) will contain the following at roughly UK DRV levels:

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Nutrient	Typical UK Daily Multivitamin Dose	UK DRV / Reference Nutrient Intake	Notes
Vitamin A	800 µg RE (often as retinol or beta-carotene)	700 µg (men), 600 µg (women)	Pregnancy formulations switch to beta-carotene only
Vitamin C	60–80 mg	40 mg	Frequently above DRV; safe ceiling 1000 mg/day
Vitamin D	5–10 µg (200–400 IU)	10 µg (NHS autumn/winter advice)	Often the weakest nutrient in generic formulas
Vitamin B12	1–2.5 µg	1.5 µg