The Most Popular Supplements in the UK and What They Are

Walk into any UK pharmacy or browse any supplement shop online and the same handful of names keep appearing: vitamin D, magnesium, omega-3, vitamin B12, vitamin C and zinc. This guide explains what each one is, where it comes from, what to look for on the label and when it is worth having a word with your doctor or pharmacist first.

What makes a supplement "popular"?

Most of the best-selling supplements in the UK are vitamins, minerals or fatty acids that people also get from food. They are familiar, they appear in official dietary advice and their roles in the body are well described. That is also why they are the only kind of supplement allowed to carry authorised health claims, the short, exact statements approved for use on food labels in the UK.

The usual names and where they come from

Vitamin D

Our skin makes vitamin D when it is exposed to summer sunlight, and small amounts come from oily fish, egg yolks and fortified foods. Between October and March the sun in the UK is too weak for this, which is why UK government advice is that everyone should consider a daily supplement containing 10 micrograms of vitamin D during autumn and winter. Vitamin D contributes to the maintenance of normal bones. Vitamin D contributes to the normal function of the immune system.

Vitamin D3 (cholecalciferol) is often made from lanolin, the natural wax in sheep's wool, so it is not always suitable for vegans. Vitamin K2 is often paired with it. Vitamin K contributes to the maintenance of normal bones.

Magnesium

Magnesium is a mineral found in green leafy vegetables, nuts, seeds, beans and whole grains. In supplements it is always bound to another compound, such as glycinate, citrate or malate. Magnesium contributes to a reduction of tiredness and fatigue. Magnesium contributes to normal psychological function.

Omega-3 (EPA and DHA)

EPA and DHA are fatty acids found mainly in oily fish such as salmon, mackerel and sardines. Fish get them from the algae at the bottom of the food chain, which is why algae-based omega-3 exists for people who do not eat fish. EPA and DHA contribute to the normal function of the heart. The beneficial effect is obtained with a daily intake of 250 mg of EPA and DHA.

Vitamin B12, vitamin C and zinc

Vitamin B12 is found almost only in animal foods, so it is a common choice for people on plant-based diets. Vitamin B12 contributes to normal energy-yielding metabolism. Vitamin C comes from fruit and vegetables, and zinc from meat, shellfish, dairy, seeds and pulses. Vitamin C contributes to the normal function of the immune system. Zinc contributes to the normal function of the immune system.

Forms and what to look for on a label

Two products with the same name can be very different. Before you buy, turn the bottle round and check:

• The amount per serving, not per pack. Some labels list one capsule, others list two or three.
• The form. Vitamin D3 or D2, magnesium glycinate or citrate, fish oil or algae.
• Elemental amounts for minerals. 650 mg of magnesium glycinate is not 650 mg of magnesium. The label should show the elemental figure.
• EPA and DHA in milligrams for omega-3, rather than just the weight of the oil.
• %NRV, the Nutrient Reference Value, which shows how the amount compares with the reference intake for an average adult.
• Suitability. Vegan, vegetarian, contains fish, gelatin capsule or plant-based HPMC capsule.

How people take them

Take any supplement as stated on the label, at the serving size the label gives, and do not exceed the recommended daily dose. Some people prefer to take fat-soluble nutrients such as vitamin D and omega-3 with a meal, and if the label gives a timing, follow it. If you take several products, add up the totals, because the same nutrient can appear in more than one of them.

Who should check with a doctor or pharmacist first

Speak to your doctor or pharmacist before taking a new supplement if any of the following apply to you:

• you are pregnant, trying for a baby or breastfeeding
• you take any prescription medication or are under medical supervision
• you are under 18 (our products are not intended for anyone under 18)
• you already take another product that contains the same vitamin or mineral, particularly high-strength vitamin D

Frequently asked questions

Do I need a supplement if I eat well?

A varied diet provides most nutrients for most people. Vitamin D in the autumn and winter months is the main exception highlighted in UK advice. If you are unsure, a GP or registered dietitian can look at your own situation.

Is a higher strength always better?

No. Higher strength simply means more per capsule. Many people do not need more than the reference intake, and some nutrients have safe upper levels. Check the %NRV and stay within the label directions.

Why do capsule weights and nutrient amounts differ on the same label?

The capsule weight includes the compound the nutrient is bound to. A mineral salt or an oil weighs more than the nutrient it carries, which is why the label lists both.

Mother Nature products

If you are looking at the most common choices in our range, these are good places to start:

• Vitamin D3 4000IU K2 MK7 200mcg Capsules: 100 µg (4,000 IU) of vitamin D3 from lanolin with 200 µg of vitamin K2 as MK-7, one capsule daily. Not suitable for vegans or vegetarians.
• Magnesium Glycinate 650mg Vegan Capsules: 130 mg of elemental magnesium per capsule (34.7% NRV), 2 to 4 capsules daily.
• Omega 3 Fish Oil 1000mg Softgels, 500mg EPA and 200mg DHA: 700 mg of EPA and DHA combined in each softgel. Contains fish.

You can see more everyday vitamins and minerals in our Daily Foundations collection.

Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle.