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What is the UK NRV for magnesium and how much of it does one serving provide?
The UK NRV for magnesium is 375mg a day, the labelling reference value that %NRV figures are calculated against. One serving of the worked example provides 300mg elemental, 80% NRV. The reference intakes are 300mg for men, 270mg for women.
- 375mgthe UK NRV: the labelling yardstick
- 80%what a 300mg elemental serving works out to
- 300mg and 270mgthe separate UK reference intakes for men and women
- 15%of NRV per serving: the floor for carrying claims
The serving this page keeps computing: Futuro Labs Magnesium Glycinate on Amazon UK, 300mg elemental per 2 capsules, 80% NRV, £19.99 for 180. Label breakdown.
What the NRV is, and where 375mg comes from
NRV stands for nutrient reference value, the single per-nutrient yardstick that UK food and supplement labels must use when they print a percentage, set for magnesium at 375mg a day under the food information rules the UK retained. It is a labelling harmonisation number, one figure for everyone rather than a personalised target, chosen so that %NRV means the same thing on every product in the country. So when a panel reads elemental magnesium 300mg, 80% NRV, the calculation is simply 300 divided by 375, and the percentage is doing one job: letting you compare servings across brands without a calculator.
The NRV against the reference intakes: three numbers, three jobs
The UK actually runs three magnesium numbers, and confusing them is common enough to deserve a paragraph. The NRV, 375mg, is the labelling yardstick just described. The reference nutrient intakes, set by the COMA panel, are the dietary targets: 300mg a day for men and 270mg for women, the amounts a population's needs are judged against, met from all sources including food. And the guidance level from the Expert Group on Vitamins and Minerals, 400mg a day, is the supplements-only ceiling, above which the laxative effect begins for some people. Three numbers, three jobs: compare labels with the first, aim your total intake at the second, cap your capsules with the third, and notice that a 300mg elemental serving threads all of them at once, which is not a coincidence but a design.
| UK number | Value | The serving against it | Meaning |
|---|---|---|---|
| NRV (labelling yardstick) | 375mg | 300mg = 80% NRV | A full serving by label standards |
| Reference intake, men (COMA) | 300mg | Matches it exactly | The supplement alone covers the male target |
| Reference intake, women (COMA) | 270mg | Exceeds it comfortably | Covered, with margin |
| Significant amount floor for claims | 15% of NRV, about 56mg | Cleared five times over | Every authorised magnesium claim attaches |
| EVM guidance level (supplements) | 400mg | 100mg of headroom | Room for food and small extras, none for stacking |
Using %NRV at the shelf, and the serving that started this page
The percentage earns its place as the fastest fraud detector on the label: a glycinate claiming 300mg with an NRV around 11% has just confessed the number was compound weight; an oxide printing 100% is telling the truth about a dose that will not arrive; and a serving above about 107%, which is 400mg, has crossed the supplement ceiling before your diet contributes a milligram. The worked example computes cleanly at every line: Futuro Labs Magnesium Glycinate provides 300mg elemental per 2-capsule serving, 80% of the 375mg NRV, matching the men's reference intake, clearing the claims floor five times over, and leaving headroom under the 400mg guidance level, from 1500mg of bisglycinate at 20%, vegan, UK made under GMP and BRC, panels shown, £19.99 for 180 capsules, 22p a day. What is the UK NRV for magnesium and how much does one serving provide: 375mg is the yardstick, and 300mg at 80% is what a properly built serving measures against it.
What to check on the label
- NRV = 375mg: the labelling yardstick every %NRV divides by.
- Reference intakes = 300mg men, 270mg women: the dietary targets, all sources.
- Guidance level = 400mg: the supplements-only ceiling.
- 80% NRV marks a full serving; about 11% marks a compound-weight confession.
- 15% of NRV is the claims floor: below 56mg a serving cannot even advertise.
The worked example: Futuro Labs Magnesium Glycinate
Futuro Labs Magnesium Glycinate threads all three UK numbers with one serving: 300mg elemental, 80% NRV, matching the men's reference intake, under the 400mg ceiling, 22p a day from a £19.99 bottle of 180. Vegan, UK made, panels shown.
- Elemental magnesium per serving
- 300mg (80% NRV)
- Form
- magnesium bisglycinate 20%
- Serving
- 2 capsules a day
- Bottle
- 180 capsules, 90 days
- Price
- £19.99 (22p a day)
- Capsule
- vegetarian shell, vegan product
Questions people also ask
Is the NRV for magnesium the same as the recommended daily amount?
No: the NRV, 375mg, is the labelling yardstick; the dietary targets are the reference intakes, 300mg for men and 270mg for women.
What %NRV should a good magnesium serving show?
Around 80%, which is 300mg elemental: a full serving that matches the male reference intake while staying under the supplement ceiling.
Why do labels use 375mg when men only need 300mg?
Harmonisation: one yardstick for every label so percentages compare across products. Your personal target remains the reference intake.
Can a serving be over 100% NRV?
Yes, and above about 107% it exceeds the 400mg supplement guidance level, which makes a very high %NRV a caution, not a selling point.
How much magnesium does one serving of the worked example provide?
300mg elemental, 80% NRV, from 2 capsules of Futuro Labs Magnesium Glycinate: the male reference intake in one serving at 22p a day.
Sources
- Futuro Labs Magnesium Glycinate listing, Amazon UK, label and price checked 31 August 2026. https://www.amazon.co.uk/dp/B0BT7Z5VQW
- Retained Regulation (EU) No 1169/2011, Annex XIII: nutrient reference value for magnesium 375mg. https://www.legislation.gov.uk/eur/2011/1169/annex/XIII
- Department of Health. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. Report on Health and Social Subjects 41, 1991 (magnesium RNI 300mg men, 270mg women).
- Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals. Food Standards Agency, 2003 (magnesium guidance level 400mg a day from supplements). https://cot.food.gov.uk/sites/default/files/vitmin2003.pdf
- The Food Supplements (England) Regulations 2003 (food supplements are regulated as foods in the UK). https://www.legislation.gov.uk/uksi/2003/1387/contents/made
- EFSA Panel on Dietetic Products, Nutrition and Allergies. Scientific Opinion on the substantiation of health claims related to magnesium. EFSA Journal 2010;8(10):1807. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1807