{"@context":"https://schema.org","@type":"DietarySupplement","id":"https://nutripedia.co.uk/items/multivitamin","url":"https://nutripedia.co.uk/items/multivitamin","name":"Multivitamin","category":"Vitamins","tagline":"Daily nutritional insurance — useful for closing dietary gaps, but no proven benefit in well-fed healthy adults.","verdict":"mixed","evidenceRating":3,"verdictSummary":"Reasonable insurance for those with documented or likely dietary gaps. NHS recommends specific single nutrients (folic acid pre-conception, vitamin D for all UK adults autumn–winter) over multis. Large RCTs in healthy adults (Physicians' Health Study II, ~14,600 men, 11 years) found no reduction in major cardiovascular events. The COSMOS-Mind sub-study suggested a small cognitive benefit in older adults, but evidence for benefit in well-nourished healthy people remains weak.","dosage":{"recommended":"1","unit":"tablet/day","timing":"With a meal containing fat (improves fat-soluble vitamin absorption)","notes":"Choose a product providing approximately 100% NRV (Nutrient Reference Value) — avoid mega-dose products. Avoid iron in male/post-menopausal formulas unless deficient. Pregnancy/planning: 400 mcg folic acid is the minimum NHS recommendation. Do not exceed EFSA tolerable upper intake levels for any single nutrient when stacking with fortified foods."},"keyBenefits":["Closes documented dietary gaps in vitamin D, folate, B12, iron, magnesium and selenium (NDNS data)","Convenient single-tablet delivery near 100% NRV for most water-soluble vitamins","Pre-conception/pregnancy formulas reliably deliver folic acid (NHS recommendation 400 mcg/day)","Useful safety net for vegans, restrictive eaters, and older adults with reduced absorption","May produce a small cognitive benefit in older adults (COSMOS-Mind sub-study, 3-year RCT)","Generally inexpensive insurance against episodic poor eating"],"warnings":["Physicians' Health Study II RCT: no reduction in major cardiovascular events in healthy men over 11 years","Mega-dose products risk exceeding EFSA tolerable upper intake levels — especially vitamin A, iron, zinc and B6","Iron in standard multis is unnecessary for men and post-menopausal women, and may be harmful long-term","Vitamin A in multis is teratogenic — pregnancy formulas use beta-carotene instead","Cannot replace a varied diet — fibre, polyphenols and food matrix effects are not in a tablet","Multiple drug interactions possible (vitamin K with warfarin, iron with thyroxine) — check with pharmacist"],"evidenceSummary":null,"dosing":null,"safety":null,"whoMightBenefit":[],"whoShouldAvoid":[],"regulatoryNotes":null,"faqs":[{"question":"Do healthy UK adults need a multivitamin?","answer":"NHS guidance is that most people get the vitamins and minerals they need from a varied, balanced diet, with two specific exceptions: all UK adults are advised to consider a 10 mcg vitamin D supplement in autumn and winter (because UK latitude means cutaneous synthesis is negligible October–March), and women who could become pregnant or are pregnant are advised to take 400 mcg folic acid daily until 12 weeks of gestation. SACN reviews of NDNS data confirm pockets of inadequacy — vitamin D, iron in menstruating women, magnesium, selenium, folate — but stop short of a population-wide multivitamin recommendation. A multivitamin is reasonable insurance for those with restrictive diets, older adults, or anyone with a documented gap."},{"question":"What does the largest RCT say about multivitamins and disease prevention?","answer":"The Physicians' Health Study II (n=14,641 male physicians aged 50+, median 11.2 years follow-up) is the largest and longest RCT of multivitamins in healthy adults. It found no reduction in major cardiovascular events (HR 1.01) but a small 8% reduction in total cancer incidence (HR 0.92). The 2022 US Preventive Services Task Force concluded the evidence was insufficient to recommend multivitamins for cardiovascular disease or cancer prevention in healthy adults, and explicitly recommended against beta-carotene and vitamin E for chronic disease prevention."},{"question":"What dietary gaps does NDNS identify in UK adults?","answer":"The UK National Diet and Nutrition Survey (NDNS) consistently shows mean intakes below the Lower Reference Nutrient Intake (LRNI) for several micronutrients in subgroups: vitamin D across the whole population, iron in girls and menstruating women, magnesium, selenium, potassium, and zinc in adolescents and some adults. SACN reports based on NDNS data have led to the universal vitamin D recommendation but have generally favoured targeted single-nutrient interventions over multivitamins. A multivitamin can act as a safety net but is not a substitute for addressing the underlying dietary pattern."},{"question":"What are the risks of taking a multivitamin?","answer":"Risks are dose-dependent. Standard formulas providing approximately 100% NRV are very safe. Mega-dose products risk exceeding EFSA tolerable upper intake levels — particularly for vitamin A (teratogenic in pregnancy at high doses), iron (oxidative damage), zinc (induces copper deficiency above 25 mg/day), B6 (peripheral neuropathy above 200 mg/day) and selenium. Beta-carotene at high doses increases lung cancer risk in smokers (CARET, ATBC trials). Pregnancy formulas use beta-carotene, not retinol, for this reason. People taking warfarin (vitamin K interaction) or thyroxine (calcium/iron interaction) should review their supplement with a pharmacist."},{"question":"Should pregnant women take a multivitamin?","answer":"NHS recommends 400 mcg folic acid daily from before conception until 12 weeks pregnant (or 5 mg in higher-risk groups including obesity, diabetes, family history of neural tube defects). All UK adults including pregnant women are advised 10 mcg vitamin D daily. Many women find a pregnancy-specific multivitamin a convenient way to deliver these alongside iron and other nutrients, but the evidence-based core is folic acid plus vitamin D. Pregnancy multis must avoid retinol-form vitamin A — large doses are teratogenic. Standard adult multivitamins are not appropriate in pregnancy."},{"question":"Does a multivitamin help cognitive function?","answer":"The COSMOS-Mind sub-study (n=2,262, 3 years, adults aged 65+) reported a small but statistically significant benefit on global cognition with daily multivitamin versus placebo — equivalent to slowing age-related decline by roughly 60% over the trial period. This is the strongest cognitive signal to date, but it has not been replicated in younger or independent populations and the absolute effect size is modest. The trial does not support multivitamin use for cognitive enhancement in healthy younger adults, but it adds to the case for multivitamins as reasonable insurance in older adults."}],"research":{"totalCount":0,"papers":[]},"machineReadable":{"markdownUrl":"https://nutripedia.co.uk/items/multivitamin/markdown","jsonUrl":"https://nutripedia.co.uk/items/multivitamin/json","llmsTxt":"https://nutripedia.co.uk/llms.txt"},"disclaimer":"Informational supplement research only. Not medical advice. Consult a qualified healthcare professional before taking supplements.","lastReviewed":"2026-05-04T00:00:00.000Z","updatedAt":"2026-05-04T00:00:00.000Z"}