How to Read a Supplement Label: NRV, Daily Portion and Warnings

Every food supplement sold in Great Britain, gummy, tablet, capsule or liquid, must show the same things: the words "food supplement", the portion to take each day, the amount of each vitamin or mineral in that daily portion and its percentage of the nutrient reference value (NRV), a warning not to exceed the stated dose, a statement that supplements are not a substitute for a varied diet, and "keep out of reach of young children".^{1, 2} The NRV is a labelling reference set in law for 27 vitamins and minerals; 100% means the daily portion carries that reference amount, and the UK's own daily figures sit above it for some nutrients (vitamin D, 10 micrograms against an NRV of 5) and below it for others (iron for men, 8.7 mg against 14 mg).^{3, 4, 5} This page belongs to the Wellgard vitamins and minerals guide.

Evidence at a glance

• Law: Food Supplements (England) Regulations 2003, regulation 6; retained Regulation 1169/2011, Annex XIII (the 27 NRVs) and Annex III (sweetener statements).^{1, 3, 6}
• Guidance: Department of Health advisory statements for vitamin A above 800 micrograms, vitamin B6 above 10 mg, iron above 20 mg and zinc above 25 mg a day.⁷
• UK daily amounts: NHS pages reviewed 3 August 2020 (review overdue); NHS pregnancy page reviewed 3 June 2026.^{4, 5, 8, 9}

Sources checked on 29 October 2026.

What must a UK supplement label show?

Regulation 6 lists the particulars, and they apply to every format alike: a gummy label carries the same statutory elements as a tablet label.^{1, 2} The product is sold under the name "food supplement"; the label names the categories of nutrient that characterise it, states the portion recommended for daily consumption, warns not to exceed the stated daily dose, states that food supplements should not be used as a substitute for a varied diet, and says "keep out of reach of young children". It gives the amount of each vitamin and mineral numerically, per daily portion, as an average based on the manufacturer's analysis, and as a percentage of the reference value.^{1, 2} The same regulation bars any label or advert from stating or implying that a balanced and varied diet cannot provide appropriate amounts of nutrients in general.¹

What does NRV mean, and what does it not?

The nutrient reference value is a single adult figure for each vitamin and mineral, written into Annex XIII of the retained food information regulation.³ It is a labelling reference, not a target and not a ceiling; it replaced "RDA" as the label term, and it is not the UK dietary figure, the reference nutrient intake the NHS quotes by sex and age. A children's product shows its percentages against these adult values.

The UK daily figures for women are tabled on how to choose a multivitamin for women.

Why is 100% not the same for every nutrient?

Because the reference value and the NHS advice were set separately. For vitamin D the NRV is 5 micrograms, while the NHS says adults and children over one need 10 micrograms a day, so 200% NRV is the NHS amount.^{3, 4} For folic acid the NRV is 200 micrograms and the NHS advises 400 micrograms a day until the twelfth week of pregnancy.^{3, 9} For iron the NRV is 14 mg against UK figures of 14.8 mg for women aged 19 to 49 and 8.7 mg for men and for women over 50.^{3, 5} Calcium and magnesium run the other way: 100% NRV is 800 mg and 375 mg, amounts that do not fit in one piece of any format, so a one-a-day product carries a small percentage and the rest comes from food.³ What a percentage above 100% means, and where the NHS ceilings sit, is the subject of high strength or 100% NRV.

What do the units and the daily portion mean?

A microgram is a thousandth of a milligram; "mcg" and "µg" are the same unit. Vitamin D is also given in international units: 1 microgram is 40 IU, so 10 micrograms is 400 IU.⁴ For minerals the number to read is the elemental amount: a label may name the compound, such as magnesium citrate, and the compound weighs several times the mineral it carries, so the %NRV settles it. A mineral gummy may need more pieces than a capsule for the same elemental amount, which is arithmetic, not a fault; is it OK to take magnesium every day works through it. Every amount on the panel is for the daily portion, not per piece: if the portion is two gummies, taking one halves the figures and taking four doubles them.^{1, 2}

What do "source of" and "high in" mean?

These are nutrition claims with fixed conditions. A product may say "source of" a vitamin or mineral when its daily portion carries a significant amount, defined in Annex XIII as 15% of the NRV, and "high in" when it carries at least twice that, 30%.^{3, 10} The 15% threshold is also the level at which a nutrient may carry its authorised health claim, and the wordings are fixed by the Great Britain register: vitamin D "contributes to the maintenance of normal bones", vitamin C "contributes to the normal function of the immune system", never "boosts".¹¹ The full set of wordings and conditions is on the GB health claims register, with single-nutrient pages for vitamin C, magnesium and zinc.

What do the sugars and sweetener lines mean?

The nutrition panel declares sugars per portion, and the figure to set it against is the NHS limit for free sugars: 30 g a day for adults, 24 g for children aged 7 to 10 and 19 g for children aged 4 to 6.¹² A product sweetened without sugar must say "with sweetener(s)" beside its name, one with both must say "with sugar(s) and sweetener(s)", and one with more than 10% added polyols must state that "excessive consumption may produce laxative effects".⁶ An online listing often leaves these lines out; the pack carries them. Sugar and sweeteners in gummy vitamins takes the sugars line further.

Which warnings should a label carry?

The Department of Health agreed voluntary advisory statements with industry in 2004 (vitamin A in 1991), each triggered by the daily amount, counting every source of the nutrient in the product.⁷ Above 800 micrograms of preformed vitamin A: "This product contains vitamin A. Do not take if you are pregnant or likely to become pregnant except on the advice of a doctor or antenatal clinic." Above 10 mg of vitamin B6: "Long term intakes of this amount of vitamin B6 may lead to mild tingling and numbness." Above 20 mg of iron: "This amount of iron may cause mild stomach upset in sensitive individuals." Above 25 mg of zinc: "Long term intake of this amount of zinc may lead to anaemia."

The vitamin A statement matters most. The NHS says not to take cod liver oil or supplements containing vitamin A (retinol) in pregnancy, and that food and supplements together should average no more than 1.5 mg a day because higher intakes over many years may affect bone.^{8, 9} In the ingredient list, "retinyl acetate" and "retinyl palmitate" are preformed vitamin A; "beta-carotene" is not. Pregnancy vitamins and what is vitamin A good for have the detail.

What can a label not tell you?

The measured content on the day you open the jar: the declared amount is an average, and manufacturers add an overage so it still holds at the end of shelf life, since no vitamin is completely stable.^{2, 7}

Who should check first?

Anyone who is pregnant or breastfeeding, anyone with kidney disease or haemochromatosis, anyone on warfarin, levothyroxine or metformin, and anyone with a diagnosed deficiency should ask their GP or pharmacist which supplement suits them. Anyone who eats liver weekly should not take a supplement containing vitamin A.⁸

What we don't know

• No published UK survey has measured declared against actual vitamin content in retail supplements across their shelf life.
• The UK publishes no statutory tolerances for declared amounts.²

Frequently asked questions

What does 100% NRV mean on vitamins?

That the daily portion carries the full nutrient reference value, the adult labelling figure set in law: 80 mg for vitamin C, 5 micrograms for vitamin D, 14 mg for iron.³

What does 50% NRV mean?

Half the reference amount in the daily portion. Where the UK figure is below the NRV, as for iron in men (8.7 mg against 14 mg), 50% is still above the UK daily amount.^{3, 5}

Is a higher NRV better?

It is a higher amount, not a better product. For vitamin D and folic acid the NHS amount itself sits at 200% NRV; for vitamin B6, vitamin A, iron and zinc the ceilings decide.^{4, 7, 9} High strength or 100% NRV goes nutrient by nutrient.

What is the NRV for vitamin D, and why do products give 200%?

The NRV is 5 micrograms; the NHS advises 10 micrograms a day, which shows as 200%.^{3, 4}

Sources

1. The Food Supplements (England) Regulations 2003, regulation 6 (labelling), as amended to 31 December 2020. legislation.gov.uk.
2. Department of Health and Social Care. Guidance notes on legislation implementing Directive 2002/46/EC on food supplements. Last updated 2 November 2021. gov.uk.
3. Regulation (EU) No 1169/2011 as retained in GB law, Annex XIII, nutrient reference values and significant amount. legislation.gov.uk.
4. NHS. Vitamins and minerals: vitamin D. Page reviewed 3 August 2020 (review overdue). nhs.uk.
5. NHS. Vitamins and minerals: iron. Page reviewed 3 August 2020 (review overdue). nhs.uk.
6. Regulation (EU) No 1169/2011 as retained in GB law, Annex III, sweetener and polyol statements. legislation.gov.uk.
7. Department of Health. Food supplements: label advisory statements and suggested reformulations. Voluntary statements agreed 2004 (vitamin A, 1991). gov.uk.
8. NHS. Vitamins and minerals: vitamin A. Page reviewed 3 August 2020 (review overdue). nhs.uk.
9. NHS. Pregnancy vitamins and supplements. Page reviewed 3 June 2026. nhs.uk.
10. Regulation (EC) No 1924/2006 as retained in GB law, Annex, conditions for "source of" and "high in". legislation.gov.uk.
11. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register. Last updated 19 May 2026. gov.uk.
12. NHS. Sugar: the facts. Page reviewed 19 May 2023. nhs.uk.

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General information, not medical advice.