Nutriluxe Editorial Team
Almost every article written about supplements assumes you take one thing. The label is explained, the percentages are decoded, the serving size is pointed out, and the piece ends there. Real routines rarely look like that. People start with one product, read something interesting a few months later, and add a second. Magnesium is one of the most common additions, partly because it appears in so many conversations about diet and partly because it is a mineral most people can name without being able to say much about it.
The moment a routine goes from one bottle to two, a different question applies. It is no longer “what is in this product?” but “what is in all of this, added together?” No label answers that second question, because no label knows what else is in your cupboard. The arithmetic is left to you, and almost nobody explains how to do it.
This piece is about that arithmetic. It uses magnesium as the worked example because it is a frequent second purchase, and because its labelling has a quirk that makes the sums look stranger than they are.
Why a second product changes the reading
A UK supplement label is a self-contained document. It tells you what is in one serving of that product, and what percentage of the Nutrient Reference Value that serving represents. It has no way of accounting for anything else, and it is not required to.
That works well in isolation. It works less well when three products sit on the same shelf and two of them quietly contain the same nutrient.
Overlap is easier to create than most people expect. Multivitamins contain long lists in small amounts. Products named after one nutrient often contain several. A formulation described as being for bones may carry four or five minerals, only one of which is on the front of the pack. Nothing about this is improper — it is simply how multi-nutrient products are built. It does mean the front label is a poor guide to what a routine actually contains.
The back panel is where the answer lives. Reading two back panels side by side takes about a minute, and it is the single most useful habit available to anyone taking more than one product.
Here is the method, and it is deliberately unsophisticated. Write down every nutrient listed on the first panel with its amount and percentage. Do the same for the second. Anything appearing on both lists gets its amounts added together. That total is what your routine supplies, and it is the figure worth holding against published reference points.
For a worked example, the Nutriluxe Vitamin D3 4,000 IU with K2 as MK-7 formulation lists vitamin D3, vitamin K2 as MK-7, calcium as calcium citrate and vitamin C as calcium ascorbate. The Nutriluxe Magnesium Glycinate Complex lists magnesium bisglycinate, magnesium malate and magnesium citrate, providing 202mg of elemental magnesium per two-capsule serving. Laid side by side, the two panels share no nutrient. That is a conclusion you can only reach by reading both — and the same exercise across two products from different brands may well produce a different answer.
The magnesium quirk, briefly
Magnesium labels look inconsistent because magnesium is never supplied on its own. It is bound to something else, and the weight printed on the ingredients list often describes the whole compound rather than the mineral inside it.
This is why one product can advertise a four-figure milligram number and another a three-figure one while both are accurate and both are describing similar amounts of magnesium. The figure that carries across products is the elemental magnesium content, which is what the nutrition panel and the NRV percentage refer to.
We have covered this in detail in our guide to magnesium forms and what the numbers on the panel mean, so it is enough to say here that when you add two labels together, you add the elemental figures. Compound weights are not comparable across products and should be left out of the sum entirely.
Magnesium also appears on the GB Nutrition and Health Claims Register, where the authorised wording states that magnesium contributes to the maintenance of normal bones. That is the phrasing permitted in Great Britain, and it describes a contribution rather than an outcome. Wording of this kind is worth recognising on a label, because it is one of the few things on a pack that has been assessed rather than written by a marketing team.
Where the published reference points sit
Several different numbers circulate for magnesium, and they are not measuring the same thing. Keeping them separate makes the arithmetic far less confusing.
The NHS gives adult figures of 300mg a day for men and 270mg a day for women aged 19 to 64, and states that a varied and balanced diet should supply this. Those figures cover total intake, food included.
The Nutrient Reference Value used for labelling in Great Britain is 375mg. This is a single labelling standard rather than a personal target, which is why a percentage on a panel will not match the NHS figures. If you have read our piece on what the percentages on a supplement label mean, that is the reference value being applied here.
There is also a published position on supplements specifically. The NHS states that having 400mg or less a day of magnesium from supplements is unlikely to cause any harm, and notes that taking too much could be harmful. The UK Expert Group on Vitamins and Minerals arrived at a comparable figure for supplemental magnesium in its review of safe upper levels. Both refer to magnesium from supplements, not from food.
Read together, these are reference points rather than instructions. What any individual should do with them is a question for that person and, where relevant, a healthcare professional. It is not something a general article can answer, and no supplement label is written with your routine in view.
Practical considerations
Check the serving size before the percentage. A percentage always relates to the stated serving, which may be one capsule, two capsules or a scoop. Two products can show the same percentage and require different numbers of capsules to get there.
Look past the headline nutrient. The name of a product describes its lead ingredient, not its contents. The full ingredients list is the only complete account.
Re-check the things you checked the first time. Capsule material, allergens, suitability for vegans or vegetarians, and any excipients used in manufacture all vary by product. Clearing one label tells you nothing about another.
Consider where the product was made. Manufacturing standards are not printed as a percentage, but they are worth knowing. Both Nutriluxe formulations are made in the UK in a GMP-certified facility in small batches, which is the kind of detail a brand should be willing to state plainly rather than imply.
Ask a pharmacist if you take prescribed medicines. Some supplements and some medicines are advised to be taken apart from one another. A pharmacist can look at your actual list, which is more useful than any general guidance.
Remember what supplements are for. Food supplements are intended to supplement a varied and balanced diet, not to replace one. Diet remains part of the total, even though it never appears on a panel.
Common questions
Does taking two products mean I am getting too much of something?
Not by itself. It means the total is worth knowing rather than assuming. If the two products share no nutrients, there is nothing to add. If they do, adding the elemental amounts and comparing the total against published reference points is the sensible check.
Is the percentage on my label a total for the day?
No. It relates to one serving of that one product. Percentages from separate products are not printed as a combined figure anywhere, which is precisely why adding them yourself is useful.
Both my products list magnesium. What do I do?
Add the elemental magnesium figures from the two nutrition panels, not the compound weights from the ingredients lists. That total is what your routine supplies from supplements, which is the figure the published supplement reference points describe.
Should I be taking magnesium at all?
That is not a question this article can answer, and it would be wrong to imply otherwise. The NHS position is that a varied and balanced diet should supply the magnesium adults need. Whether any particular person’s diet does is an individual matter, best discussed with a healthcare professional.
Why do the NHS figure and the label percentage disagree?
Because they were set for different purposes. The NHS figures describe dietary intake for UK adults. The 375mg Nutrient Reference Value is a labelling standard applied uniformly across products so that percentages remain comparable. Neither is wrong; they are simply not the same measurement.
Key takeaways
A supplement label describes one product and cannot describe a routine. Once you are taking more than one, the useful reading happens across two back panels rather than within one. List the nutrients, add anything that appears twice, and work in elemental magnesium rather than compound weights when magnesium is involved.
Three published figures are worth keeping distinct: the NHS adult dietary figures of 300mg and 270mg, the 375mg Nutrient Reference Value used for labelling, and the separate position on magnesium from supplements. They answer different questions and are not interchangeable.
The GB Nutrition and Health Claims Register recognises that magnesium contributes to the maintenance of normal bones, which is the authorised wording in Great Britain. Beyond that, the most valuable thing on any pack is a full ingredients list you can actually read — and the willingness to read a second one alongside it.
References
- NHS. Vitamins and minerals — Others. nhs.uk
- NHS. Vitamins and minerals. nhs.uk
- Great Britain Nutrition and Health Claims Register. Department of Health and Social Care. gov.uk
- Expert Group on Vitamins and Minerals. Safe Upper Levels for Vitamins and Minerals. Food Standards Agency, 2003.
- British Nutrition Foundation. Minerals and trace elements. nutrition.org.uk
- Retained Regulation (EU) No 1169/2011 on the provision of food information to consumers, Annex XIII (Nutrient Reference Values).
This article is for general information and educational purposes only. It does not constitute medical, nutritional, or professional health advice. Always consult an appropriate healthcare professional before making decisions relating to supplements or your health.