Magnesium in combination supplements: how much?
Futures Nutrition Editorial Team · 14 August 2026
Magnesium in combination supplements: how much?
When a tub carries "with magnesium" next to its main ingredient, the amount is almost always the same one: 56.25 mg per daily portion, which is 15 % of the nutrient reference value. That is precisely the legal minimum from which a manufacturer may print the word magnesium on the pack at all. The large figure on the front, by contrast, hardly ever refers to the magnesium itself, but to the compound it sits in — or to the plant beside it.
This article shows where the figure that counts is printed, how to convert from the compound to elemental magnesium, and how to add up several preparations without miscalculating.
Three places where "magnesium" appears on the pack
On a combination supplement the word turns up as often as three times — and only one of the three answers the question about the amount.
- The front. Here you find the product name and often a milligram figure. It may refer to the compound, to the starting quantity of a plant extract or to the whole tablet. As a nutrition declaration it is not regulated.
- The nutrition table. This holds the line that matters: the amount per recommended daily portion and the percentage of the nutrient reference value. Under § 4(3) of the German Food Supplements Ordinance (NemV) these are average values based on the manufacturer's analysis of the product — measured, in other words, not estimated. This figure always means the elemental magnesium, whatever the compound.
- The ingredients list. Here the compound itself is named, magnesium oxide or magnesium citrate for instance. Often "magnesium" appears a second time, as the anti-caking agent magnesium salts of fatty acids. That is a technological aid in the single-digit milligram range; arithmetically it adds fractions of a milligram to the magnesium content and is not counted.
Rule of thumb for the shelf: ignore the front, read the nutrition table.
Converting the compound into the element
Magnesium never sits in a tablet on its own, always bound to a partner — and the partner weighs something too. The share that is actually magnesium is called the elemental content, and it varies by more than fourfold. That is why the raw-material amount in the ingredients list says nothing without conversion:
| Compound | Elemental content (approx.) | Raw material for 56.25 mg | Raw material for 150 mg |
|---|---|---|---|
| Magnesium oxide | 60 % | 94 mg | 250 mg |
| Magnesium carbonate | 28 % | 201 mg | 536 mg |
| Magnesium citrate | 16 % | 352 mg | 938 mg |
| Magnesium malate | 15 % | 375 mg | 1,000 mg |
| Magnesium bisglycinate | 14 % | 402 mg | 1,071 mg |
The last column explains why combination supplements nearly always contain magnesium oxide: in a tablet that also has to make room for a plant extract, a second mineral and a filler, 94 mg of raw material is feasible and 402 mg is not. How the forms differ in other respects is set out in Magnesium forms compared.
Important in practice: the ingredients list usually names the compound without an amount. Then the path cannot be walked backwards — the nutrition table is the only sound source. The other direction always works: if it says "Magnesium 56.25 mg (15 %)", that is the figure to calculate with, whatever compound appears below it in the ingredients list.
Why it is so often exactly 15 %
The number is no coincidence but a threshold. The nutrient reference value for magnesium is 375 mg per day under Annex XIII Part A of Regulation (EU) No 1169/2011; 15 % of it counts as a significant amount, and 15 % of 375 mg is precisely 56.25 mg.
From that threshold on, two things happen. First, under the Annex to Regulation (EC) No 1924/2006 the manufacturer may print "source of magnesium" or words to that effect on the pack at all. Second, they may use the authorised health claims set out in Regulation (EU) No 432/2012 — every one of them tied to the condition that the product meets the minimum requirements for a source of magnesium. Below 56.25 mg, practically nothing could stand on a hawthorn or herb tub apart from the ingredients list.
The next step up is twice as high: "high magnesium content" requires, under the same Annex, at least double the source value, that is 112.5 mg or 30 % of the nutrient reference value. Anyone who knows these two figures reads any combination pack in seconds: 56.25 mg means the minimum, 112.5 mg means deliberately dosed higher.
Our Hawthorn + magnesium is one such case: 56.25 mg of magnesium from magnesium oxide per tablet, alongside the berry extract in a 20:1 ratio. The two figures answer different questions. The 20:1 describes the plant extract and says nothing about the mineral; the magnesium line is the one that carries the wording on the pack.
"Per daily portion" is not "per tablet"
The commonest mistake when comparing two combination supplements lies in the reference quantity. § 4(2) NemV requires the recommended daily intake to be stated in portions — and a portion may be one, two or three tablets. Every figure in the nutrition table refers to that portion, not to the individual piece.
Two products with an identical table can therefore differ by a factor of three:
- Product A: 60 mg of magnesium per daily portion, portion = 1 tablet → 60 mg per tablet.
- Product B: 60 mg of magnesium per daily portion, portion = 3 tablets → 20 mg per tablet, and the tub is empty after a third of the days.
For a price comparison, then, always calculate per daily portion and per day, never per tablet. How that works in detail is set out in Buying magnesium: compare the price per mg properly.
Adding up several preparations
Magnesium sits in more preparations than one keeps in mind: in plant combinations, in mineral blends, in sports drink powders, in calcium-magnesium products. Anyone taking several alongside each other adds these amounts up — and the one figure the result can sensibly be held against is the maximum-level proposal of the German Federal Institute for Risk Assessment (BfR): 250 mg of magnesium per day from food supplements, spread over at least two intakes. The decisive effect above that is osmotic diarrhoea, not a risk of poisoning.
A worked example with two products from our range:
| Preparation | Daily portion | Magnesium | Share of NRV |
|---|---|---|---|
| Hawthorn + magnesium | 1 tablet | 56.25 mg | 15 % |
| Magnesium bisglycinate 150 mg | 1 tablet | 150 mg | 40 % |
| Total | 206.25 mg | 55 % |
That stays below the 250 mg. Add an electrolyte powder with 100 mg and it would be 306 mg — above. The 375 mg of the nutrient reference value are no counter argument, by the way: they apply to total intake including food and drink, the 250 mg only to what comes on top of it. Why the two figures do not contradict each other is set out in Too much magnesium: reading the 250 mg limit.
When the combination supplement is enough — and when it is not
The authorised claims belong to the nutrient, not to the dose: Magnesium contributes to normal muscle function. and Magnesium contributes to the reduction of tiredness and fatigue. may be used from 56.25 mg per daily portion onwards. That does not mean 15 % of the nutrient reference value and 40 % of it achieve the same thing.
In practice the decision goes like this:
- You want the other ingredient — the plant extract, the vitamin, the second mineral. Then the magnesium is a small addition, and 15 % is enough.
- You want magnesium specifically. Then the way leads through a single-ingredient product. Our Magnesium bisglycinate 150 mg supplies 150 mg of elemental magnesium per tablet; the remaining compounds are in the magnesium category, combinations with plant extracts in the hawthorn category.
Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.
Frequently asked questions
Does the magnesium in the anti-caking agent count? No. Magnesium salts of fatty acids contain around 4 % magnesium; with 10 mg of anti-caking agent that is about 0.4 mg. It plays no part in the daily balance, and it does not appear in the nutrition table as a nutrient portion. Anyone skimming the ingredients list and reading "magnesium" twice should therefore not count twice.
The front shows a far bigger number than the table. Is that allowed? As a rule yes — the two figures mean different things. "500 mg" on the front may refer to the compound that yields 80 mg of elemental magnesium, or to the starting quantity of an extract. The binding statement is the nutrition table with its reference to the daily portion.
Is magnesium oxide in a combination supplement the poorer choice? It is the space-saving choice. Oxide has the highest elemental content but dissolves less readily than organic compounds; in absorption studies organic forms tend to do better, with differences that vary in size from study to study. The authorised claims do not distinguish between compounds.
How do I spot a combination supplement in which magnesium is only a sideline? By two signs: the share is exactly 15 % of the nutrient reference value, and the magnesium appears far down the ingredients list. That is not a defect but a design — one should simply not mistake it for a magnesium supplement.
Sources: Regulation (EU) No 1169/2011, Annex XIII Part A (nutrient reference value for magnesium 375 mg; significant amount 15 %) · Regulation (EC) No 1924/2006, Annex, entries "source of [name of vitamin/s] and/or [name of mineral/s]" and "high [name of vitamin/s] and/or [name of mineral/s]" (at least double) and recital 20 · Regulation (EU) No 432/2012, authorised claims for magnesium with the condition "minimum requirements for a source of magnesium" · German Food Supplements Ordinance (NemV) § 4(2) and § 4(3) · German Federal Institute for Risk Assessment, maximum-level proposal for magnesium in food supplements (250 mg/day, 2017) · Scientific Committee on Food, Tolerable Upper Intake Level of Magnesium, 2001 · Product declarations Hawthorn + magnesium (180 tablets) and Magnesium bisglycinate 150 mg (120 tablets).
