Vitamins & Supplements

Do you need vitamins and supplements?

Most people don't: the NHS says most people should get all the nutrients they need from a varied and balanced diet, although some people may need to take extra supplements. Supplements add to a good diet; they don't replace one.

The useful question is not "what should I take?" but "is there a specific reason for me to take this?" The NHS advice below covers the clearest reasons, and our guide to what supplements you actually need goes through the rest.

Which vitamins does the NHS recommend?

The NHS advises everyone to consider a daily vitamin D supplement in autumn and winter, and it gives specific advice for pregnancy, young children and vegans. Those are the main situations where a supplement is officially recommended.

Browse vitamin D, B vitamins & B12 and kids' vitamins.

How much vitamin D should you take?

The NHS advice for adults is 10 micrograms (400 IU) a day, and not to take more than 100 micrograms (4,000 IU) a day, as that could be harmful. One microgram of vitamin D equals 40 IU, which helps when labels use different units.

Some vitamin D products contain much more than 10 micrograms per tablet, so check the amount per daily dose before you buy. Taking too much vitamin D over a long period can cause too much calcium to build up in the body.

Is vitamin D the same as vitamin D3?

Vitamin D3 is one form of vitamin D, and D2 is another. The British Dietetic Association says vitamin D3 is the most effective, while D2 is a plant-based alternative suitable for vegetarians and vegans.

"Vitamin D2 and D3 aren't identical, and customers may not realise the difference," says Andy Arshad, who runs SupplementHQ. Check which form is on the label, especially if you need a vegan product.

Does a higher dose mean a better supplement?

No. A higher dose doesn't automatically mean better results, and for some nutrients too much can be harmful: the NHS says, for example, that taking 17mg or less of iron a day from supplements is unlikely to cause harm, while higher doses can cause side effects.

"Some supplements advertise 1,000% or more of the Nutrient Reference Value, making them appear more powerful," says Andy. "But a higher dose doesn't automatically mean better results, and in some cases, excessive intake can be harmful. We want customers to understand what they're taking rather than simply choosing the highest numbers on the label." Our guide to reading a supplement label explains what %NRV does and doesn't mean.

Does the form of a vitamin or mineral matter?

It can: the same nutrient is often sold in different forms, such as magnesium oxide, citrate or glycinate, so check the form as well as the amount on the label. The NHS says 400mg or less a day of magnesium from supplements is unlikely to cause harm.

"Magnesium oxide, citrate and glycinate are often sold under the same general category, but they differ in absorption, tolerability and price," says Andy. "Two products that look almost identical on the shelf can offer different value." Browse magnesium.

Multivitamin or single vitamins?

A multivitamin covers many nutrients in one daily dose, while a single supplement gives you one nutrient, often at a higher amount. If you take both, add up the amounts so you don't double up on the same nutrient.

Compare multivitamins on the amount of each nutrient per daily dose, not just the number of ingredients on the front.

Are vitamin gummies worth it?

Gummies are convenient, but they often cost more per serving than tablets or capsules, and some contain added sugars or sweeteners. Compare the amount of the active ingredient per daily dose and the cost of that dose, not just the format.

"We think customers should compare the actual amount of active ingredients they're getting, rather than just the format or marketing," says Andy.

How to compare value (example figures, not real products): a £6 pot of 90 vitamin D tablets, one a day, costs about 7p a day. A £12 pot of 60 gummies, two a day for the same amount, costs 40p a day, six times as much for the same dose. Browse vitamin gummies.

Can you take too many vitamins?

Yes. Some vitamins and minerals can be harmful in large amounts: the NHS warns that taking too much vitamin D for a long time can harm the bones, kidneys and heart, and that very high doses of iron can be fatal, particularly for children.

Keep supplements out of children's reach, check for the same nutrient across everything you take, and follow the dose on the label. If you're pregnant, the NHS says not to take supplements containing vitamin A (retinol) or cod liver oil. If you take medication or have a medical condition, speak to your GP or pharmacist before starting a supplement.

How do you choose a good vitamin brand?

Look at the amount of each nutrient per daily dose, its form, the cost per serving and any testing or certification, rather than the brand name or the price alone. A more expensive product isn't automatically a better one.

"I've noticed substantial differences in prices between brands offering similar ingredients and dosages," says Andy. "Sometimes the premium is justified by formulation, testing or ingredient quality, but sometimes customers are paying mainly for branding. My biggest takeaway from sourcing these products is that customers need more transparency, not more marketing claims."

That's how we compare vitamins at SupplementHQ: ingredients, doses, forms, evidence and cost per serving, and we say so when the evidence behind a supplement is limited. Start with vitamin D, multivitamins or magnesium.

We sell the products on this page. That's our commercial interest, and it's why we show the evidence alongside them. This page is general information for adults, not personalised medical advice. Food supplements should not replace a varied, balanced diet.

Written by Andy Arshad, SupplementHQ. Last reviewed 10 October 2026.