Most supplement labels have a column headed %NRV. It is one of the most useful numbers on the pot, and one of the most often misread. Here is what it means, and how to use it sensibly.
What an NRV is
NRV stands for Nutrient Reference Value. NRVs are fixed daily reference amounts for 13 vitamins and 14 minerals, set for adults in UK food labelling law. They give every label the same yardstick, so you can compare one product with another. Older labels used the term RDA, short for recommended daily allowance, for a similar idea.
An NRV is not a personal target. How much of a nutrient you need depends on things like your age, sex and stage of life. The NRV is simply a fixed point for comparison.
How to read “25% NRV”
The percentage tells you how much of the reference amount a stated serving provides. Take ACV MetaBoost. Each capsule provides 10 µg (micrograms) of chromium. The NRV for chromium is 40 µg, and 10 divided by 40 is a quarter, so the label shows 25%.
Always check what the serving is. ACV MetaBoost’s table is per capsule, and the directions are 1 capsule, 2 to 3 times a day. A full day’s dose therefore provides 20 to 30 µg of chromium, which is 50 to 75% NRV.
As a rule, labelling law treats 15% of the NRV as a “significant amount”. That matters for health claims: a claim about a vitamin or mineral can only be made when the product provides at least that much of it.
Why many ingredients have no NRV
NRVs exist only for those 27 vitamins and minerals. Everything else has none, including plant extracts, amino acids, fatty acids, collagen, caffeine and vinegar. That is why the %NRV column is blank for them, or marked with a symbol that a footnote explains.
On ACV MetaBoost, apple cider vinegar, green tea leaf, cayenne pepper, ginger root, turmeric root and black pepper each have an amount in milligrams but no percentage. A blank NRV says nothing good or bad about an ingredient. It only means there is no official reference amount to compare it with. For these ingredients, look at the amount and the form, such as whether it is a powder or an extract.
Why more is not automatically better
It is tempting to read 100% as a pass mark and anything above it as better. %NRV does not work like that, and a higher percentage is not a sign of a better product. The NHS says most people should get all the nutrients they need from a varied and balanced diet, though some people may need to take extra supplements.
Nutrients also add up. What you eat, fortified foods and every supplement you take all count towards your total, and some vitamins and minerals can be harmful in large amounts. The NHS notes, for example, that high doses of zinc reduce the amount of copper the body can absorb. Three of our formulas, BrainLink, LuminaGlow and BioFlora Guard, contain zinc. If you take more than one of them, check each label, and ask a pharmacist if you are unsure.
Using %NRV sensibly
A few habits make the numbers easier to use:
- Check whether the table is per capsule or per daily dose.
- Add up the same nutrient across every supplement you take.
- Remember that food and fortified drinks count too.
- Stick to the dose on the label.
Why you should not exceed the stated dose
The recommended daily dose applies to the whole capsule, not to one nutrient. Taking extra capsules means taking more of every ingredient at once, including those with no NRV and no percentage to guide you. That is why every food supplement must carry a warning not to exceed the recommended daily dose. Follow the directions on the label. If you are unsure whether a supplement is right for you, ask a pharmacist or GP rather than changing the dose yourself.
You can see ACV MetaBoost’s per-capsule table, with chromium at 25% NRV, on the ACV MetaBoost page. To see every ingredient in our four formulas, including those without an NRV, visit ingredients A–Z, or browse the range in our shop.
