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The honest vitamin guide
Vitamins: the short UK list that matters, and the noise to ignore
Here is the truth the vitamin aisle will not tell you: if you eat a reasonable diet, most vitamin pills do nothing measurable for you. Large evidence reviews keep finding the same thing. But a few specific situations are different, and in the UK one vitamin is recommended to almost everyone. That is what this page is for: the short list worth your money, and the long list that is mostly marketing.
Worth taking: the evidence-backed UK list
Vitamin DThe one near-universal UK recommendation. From October to March, sunlight in Britain is too weak for your skin to make enough, so the NHS advises everyone to consider 10 micrograms (400 IU) a day. All year if you are rarely outdoors, have darker skin, or cover up. Cheap, safe at that dose, genuinely useful for bones and muscles.
Folic acid400 micrograms daily if you could become pregnant, from when you start trying until week 12. It prevents neural tube defects, and the evidence for that is rock solid. Higher doses are prescribed for some people, so check with your GP if you have diabetes or take epilepsy medication.
Vitamin B12 (if vegan)B12 comes almost entirely from animal foods. If you are fully plant-based, you need a supplement or reliably fortified foods, full stop. Deficiency creeps up over years and can cause permanent nerve damage, so this one is non-negotiable on a vegan diet.
Vitamins A, C and D for childrenThe NHS recommends daily drops for children aged 6 months to 5 years (unless they drink a lot of formula). Healthy Start vouchers cover them for many families.
Mostly noise: where the marketing outruns the science
Multivitamins "for health"The US Preventive Services Task Force reviewed the evidence in 2022 and found multivitamins do not prevent heart disease or cancer in healthy adults. One caveat: on GLP-1 treatment you eat much less, so a basic multivitamin as cheap insurance is a reasonable conversation with your prescriber. That is gap-covering, not a health hack.
Megadose vitamin CRegular vitamin C does not stop you catching colds. Taken daily it may shorten one slightly; taken after symptoms start it does nothing reliable. Your kidneys excrete what you cannot use, which is a polite way of saying expensive urine.
Biotin for hair and nailsBiotin only improves hair and nails if you are genuinely deficient, which is rare. Bonus problem: high-dose biotin interferes with common blood tests, including thyroid and troponin (the heart attack marker). Tell your GP if you take it.
"Immune support" blendsYou cannot boost a healthy immune system with a pill, and you would not want to: an overactive immune system is called autoimmune disease. Sleep, vaccination and not smoking do the real work.
IV vitamin dripsWellness-clinic drips bypass your gut's regulation for no proven benefit in healthy people, add infection and vein risks, and cost a fortune. The NHS uses IV vitamins for actual medical deficiencies. That is a different thing entirely.
More is not better: the doses that hurt
Fat-soluble vitamins (A, D, E and K) build up in the body rather than washing out. Too much vitamin A damages the liver and bones, and it can harm an unborn baby, which is why pregnant women are told to avoid vitamin A supplements and liver products. Too much vitamin D raises blood calcium to dangerous levels. Even water-soluble B6 causes nerve damage at high doses over time. The safe move is simple: stick to recommended amounts, and treat "high strength" labels as a warning, not a selling point.
Why food beats pills
An orange is not just vitamin C. It is fibre, water, potassium and hundreds of plant compounds that interact in ways no capsule copies. That is why trial after trial finds that nutrients in food are linked to better health while the same nutrients in pills mostly are not. Spend the supplement budget on better groceries first: vegetables, fruit, pulses, nuts, oily fish, dairy or fortified alternatives. Then use the short list above for the genuine gaps. Our diet reviews flag the specific nutrient risks of every pattern, and our minerals guide covers iron, calcium, magnesium and the rest the same way.
The research behind this page
We link the actual research, not press releases. These are the papers and reviews the numbers on this page come from.
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