Vitamins, minerals and herbal capsules sold in the UK are usually food supplements. Legally they are a kind of food, not a medicine. That has two practical consequences: they are not tested and licensed in the way medicines are, and they are not allowed to claim that they treat, prevent or cure any disease.
Most people who eat a varied diet get the nutrients they need from food. The NHS does recommend a few supplements for particular groups, such as vitamin D in autumn and winter and folic acid before and in early pregnancy. Beyond that, whether a supplement is worth taking depends on your diet, age and health, which is a good conversation to have with a pharmacist.
This guide explains how to read the label so you know what you are buying and how much of it you are taking. It is general information, not medical advice.
What the label must tell you
A food supplement sold in the UK has to carry certain information on the pack. Look for:
- The nutrients or substances it contains, by name.
- The amount per daily dose, for example 10 micrograms of vitamin D per tablet.
- The recommended daily dose and a warning not to exceed it.
- A statement that supplements should not replace a varied diet.
- A warning to keep the product out of reach of young children.
- %NRV for vitamins and minerals (see below).
Health claims on the pack, such as “vitamin C contributes to the normal function of the immune system”, must come from an approved list and use approved wording. Anything that sounds like a cure, or names a disease, should make you wary, whatever the product.
What %NRV means
NRV stands for Nutrient Reference Value: roughly the daily amount of a vitamin or mineral that meets the needs of most healthy adults. A tablet labelled “100% NRV” provides that amount in one dose. Higher numbers are not automatically better.
| On the label | What it tells you |
|---|---|
| 100% NRV | About a day’s reference amount for an adult |
| 500% NRV | Five times the reference amount in one dose |
| No %NRV | Usually a herb or other substance without a reference value |
| µg or mcg | Micrograms, a thousandth of a milligram |
| IU | International units, still used for vitamin D (1 microgram = 40 IU) |
For some nutrients, regularly taking far more than you need can cause harm. The NHS gives upper limits for several of them; for vitamin D, for example, it advises adults not to take more than 100 micrograms (4,000 IU) a day. If you take more than one product, add up the amounts of each nutrient across all of them, including any multivitamin.
Advice for particular groups
The NHS advice for people in the UK includes:
- Vitamin D: everyone should consider 10 micrograms a day in autumn and winter, and some people at higher risk of low levels all year round.
- Pregnancy: 400 micrograms of folic acid a day before conception and until 12 weeks of pregnancy, and avoiding supplements that contain vitamin A (retinol) or fish liver oil.
- Young children: vitamins A, C and D drops are recommended for most children from 6 months to 5 years.
If you are pregnant, breastfeeding, taking medication, waiting for surgery, or have a long-term condition, ask a pharmacist or GP before starting any supplement. Some, particularly herbal products, can interact with medicines.
Herbal capsules and blends
Ranges such as Nature’s Sunshine include many single herbs and herbal combinations in capsules. Most are sold as food supplements. A few herbal products in the UK carry a THR mark, which shows they are registered with the MHRA as traditional herbal medicines and have met set standards for quality, safety and product information. Without that mark, a herbal capsule has not been through that process.
When comparing herbal products, check:
- the Latin name of the plant and the part used (root, leaf, seed),
- how much of the herb is in each capsule and in the full daily dose,
- whether it is a whole herb powder or an extract,
- what else is in the capsule, including fillers and the capsule material (gelatine or vegetable), which matters if you are vegetarian or vegan.
Children’s supplements and pet supplements
Chewable bears and gummies, like those in the Healthy Rascals range, look and taste like sweets. Store them out of sight and reach, give only the stated dose, and do not combine them with other children’s vitamins without checking the totals. Iron in particular can be dangerous to young children in large amounts.
For animals, the Nutri-Pets range has supplements for pets, most of them for dogs. Ask your vet before adding any supplement to a pet’s diet, especially if the animal is on medication.
Comparing price fairly
Supplement packs vary in size and dose, so compare the cost of a daily dose rather than the cost of a tub:
- Divide the price by the number of tablets, then multiply by the number taken each day.
- Check whether a “month supply” means 28, 30 or 31 days at the recommended dose.
- Compare like with like: the same nutrient, in the same form, at a similar dose.
The powder category includes protein powders and drink mixes; the guide to choosing a plant protein powder covers those.
Quick checklist
- Check whether you need it at all; a pharmacist can help.
- Read the amount per dose and the %NRV.
- Add up nutrients if you take more than one product.
- Never take more than the recommended daily dose.
- Look for the THR mark if you want a registered herbal medicine.
- Ask a pharmacist or GP first if you are pregnant or on medication.
- Store children’s vitamins out of reach.
- Compare price per daily dose, not per tub.
Common questions
Are supplements checked before they go on sale?
Food supplements must be safe and correctly labelled, and local authorities enforce the rules, but they are not tested and licensed before sale the way medicines are. That is why medical claims are not allowed on them.
Is a higher dose better?
No. Above what your body needs there is usually no extra benefit, and for some vitamins and minerals large doses over time can be harmful. Stick to the label and the NHS guidance.
Can I take supplements with my prescription medicines?
Sometimes, but not always. Some vitamins, minerals and herbs change how medicines work. Show the pack to your pharmacist before you start.
