Short answer: vitamin C, vitamin D, vitamin A, vitamin B6, vitamin B12, folate, iron, copper, zinc and selenium can all carry an authorised Great Britain claim that they contribute to the normal function of the immune system, provided the product meets the claim’s conditions of use.
This is a guide to label wording, not a claim that taking more of each nutrient will prevent illness.
Immune-support nutrients at a glance
| Nutrient | Authorised immune wording | Common food sources |
|---|---|---|
| Vitamin C | Contributes to the normal function of the immune system | Peppers, citrus fruit, berries, broccoli and potatoes |
| Vitamin D | Contributes to the normal function of the immune system | Oily fish, egg yolks and fortified foods; sunlight is also important |
| Vitamin A | Contributes to the normal function of the immune system | Cheese, eggs, oily fish and beta-carotene-rich vegetables |
| Vitamin B6 | Contributes to the normal function of the immune system | Poultry, fish, oats, bananas and fortified cereals |
| Vitamin B12 | Contributes to the normal function of the immune system | Meat, fish, milk, cheese, eggs and fortified foods |
| Folate | Contributes to the normal function of the immune system | Leafy vegetables, broccoli, peas, chickpeas and kidney beans |
| Iron | Contributes to the normal function of the immune system | Meat, beans, nuts and fortified cereals |
| Copper | Contributes to the normal function of the immune system | Nuts, shellfish and offal |
| Zinc | Contributes to the normal function of the immune system | Meat, shellfish, dairy foods, bread and cereals |
| Selenium | Contributes to the normal function of the immune system | Fish, meat, eggs and some nuts |
What an authorised claim does — and does not — mean
An authorised claim is wording permitted for commercial use after assessment under the nutrition and health-claims framework. It does not mean that every product containing a trace of the nutrient may use it: the food or supplement must meet the relevant conditions.
“Contributes to normal immune function” describes a normal physiological role. It does not mean “boosts immunity”, prevents colds, treats flu or protects the user from infection. Food supplements cannot claim or imply that they treat, prevent or cure disease.
What does %NRV mean?
NRV means Nutrient Reference Value. The percentage shows how much of the labelling reference amount a stated serving provides. It is useful for comparing quantities across products.
%NRV is not:
- a personalised daily requirement;
- a treatment dose;
- a measure of how effective a product will be; or
- an upper safe limit.
Always check whether the percentage applies per capsule or to the full daily serving.
Why vitamin D is different in a UK buying decision
The NHS advises that everyone should consider taking 10 micrograms of vitamin D daily during autumn and winter. People who have little or no sunshine exposure, and some other groups, are advised to consider it throughout the year. This is population guidance about vitamin D intake; it is not a reason to assume that every “immune” blend is necessary.
What about vitamin C?
Vitamin C contributes to normal immune function and also contributes to the protection of cells from oxidative stress. It is widely available from fruit and vegetables. The NHS says adults need 40mg a day and that most people should be able to obtain enough from a varied diet. It also warns that more than 1,000mg a day can cause stomach pain, diarrhoea and flatulence.
What about zinc and selenium?
Both zinc and selenium contribute to normal immune function and to the protection of cells from oxidative stress. Compare the declared amount and %NRV, and remember to count any zinc or selenium in a multivitamin or other specialist formula. A higher percentage is not automatically a better choice.
Do botanicals and live cultures carry the same claim?
No. Ingredients such as elderberry, echinacea, garlic, reishi and live cultures should not inherit an immune claim simply because they appear beside vitamin C, vitamin D or zinc. Compare botanical species, plant part, extract details and quantity; compare live cultures by identity, CFU per serving and shelf-life guarantee. Those details describe what is present without promising an unauthorised effect.
How our Immunity Pro-Shield label fits this guide
Immunity Pro-Shield contains five nutrients with authorised immune-function claims: vitamin C, vitamin D, vitamin B6, zinc and selenium. The product provides 512mg vitamin C per capsule, equal to 640% NRV. Its other ingredients are declared separately; the authorised immune claims come from the qualifying nutrients.
The bottle contains 60 capsules. At the label direction of 1 capsule taken 1–3 times daily, it lasts 20–60 days. This practical information helps compare cost and convenience, but it does not make the product suitable for everyone.
How to read an immune-nutrient label
- Find the exact nutrient and amount.
- Check whether the figures are per capsule or per daily serving.
- Read the %NRV as a comparison reference, not a target.
- Look for the exact authorised wording.
- Separate claim-bearing nutrients from botanicals and other supporting ingredients.
- Check the directions, cautions, pack duration and daily cost.
- Add up overlapping nutrients across every supplement you use.
Frequently asked questions
Which vitamin is most important for the immune system?
There is no single answer: several vitamins and minerals contribute to normal immune function. Your dietary intake and individual circumstances matter more than a marketing hierarchy. Vitamin D deserves particular attention in the UK because of the NHS autumn and winter advice.
Is 100% NRV better than 15% NRV?
It is a larger declared amount relative to the reference value, but it does not automatically mean a better product or result. Check your total intake, the product directions and whether you already use another source.
Do immune nutrients stop me catching a cold?
The authorised claim is about normal immune function, not prevention or treatment of colds. Seek NHS advice for symptoms and do not use a food supplement as a replacement for medical care or vaccination.
Can I get these nutrients from food?
Many people can obtain most vitamins and minerals from a varied, balanced diet. NHS guidance recommends vitamin D supplementation for the population in autumn and winter, with year-round advice for some groups.
How this guide was checked
Claim wording was checked against the Great Britain Nutrition and Health Claims Register, last updated 19 May 2026. General intake and food-source information was checked against current NHS vitamin and mineral guidance. Product information was checked on 3 August 2026.
Sources and further reading
- Department of Health and Social Care — Great Britain Nutrition and Health Claims Register
- GOV.UK — nutrition and health claims guidance
- NHS — vitamins and minerals
- NHS — vitamin C
- NHS — vitamin D
Continue reading
- How to compare UK immune-support supplements
- How the immune system works
- How to read a supplement label line by line
Written by Barry Lees, founder of The Health Improvers. Educational information only; not medical advice. Food supplements are not a substitute for a varied, balanced diet and healthy lifestyle. Always read the label.
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