What is in the tablet
OstroVit Magnesium + Potassium with B6 uses the citrate salts of both minerals. The nutrition table on the label lists these amounts:
| Nutrient | Per tablet (daily dose) | % NRV | NRV for adults |
|---|---|---|---|
| Magnesium | 56.25 mg | 15% | 375 mg |
| Potassium | 300 mg | 15% | 2000 mg |
| Vitamin B6 | 0.21 mg | 15% | 1.4 mg |
15% of the NRV is the smallest amount at which a product counts as a source of a nutrient and may use its health claims. This tablet sits exactly at that threshold for all three. A pack of 60 tablets lasts 60 days.
Why magnesium and potassium go together
Both minerals are electrolytes: they carry an electric charge in body fluids. The EU allows magnesium a claim about electrolyte balance, and it allows both minerals claims about muscle function and the nervous system. That overlap is why manufacturers pair them. There is no authorised claim for the combination itself, so each statement below belongs to one nutrient.
Most potassium comes from food
The NIH Office of Dietary Supplements lists fruit, vegetables, potatoes, beans and lentils, dairy products and meat among the main food sources of potassium, and notes that many supplements contain only small amounts of it. The 300 mg in this tablet tops up what you eat. It does not replace a diet with enough fruit and vegetables.
When this product fits
The tablet suits you if you want a small daily amount of magnesium and potassium in one unit. For magnesium alone, 56.25 mg is a low dose. Most magnesium products in our range give 150 to 400 mg a day. If you add a separate magnesium supplement, count the elemental magnesium from both and keep each one within its label dose.
Treat potassium with more care. Do not stack several potassium products on your own. If you take any medication, ask a doctor or pharmacist before you start, because some medicines change how the body handles potassium.
How to take it
The label gives one tablet a day, 15 minutes after a meal, with water. The tablets are made in a facility that also handles milk, soy, nuts, gluten, eggs, crustaceans and fish, so check the allergen note if any of these matter to you.
EU health claims
Regulation (EU) No 432/2012 allows these statements for products whose daily dose gives at least 15% of the NRV of the nutrient:
- Magnesium contributes to electrolyte balance.
- Magnesium contributes to normal muscle function.
- Magnesium contributes to a reduction of tiredness and fatigue.
- Magnesium contributes to normal functioning of the nervous system.
- Potassium contributes to normal muscle function.
- Potassium contributes to normal functioning of the nervous system.
- Potassium contributes to the maintenance of normal blood pressure.
Questions
Why is there so little magnesium?
The manufacturer set each nutrient at 15% of the NRV, the minimum for a source. If magnesium is your main reason for buying, a magnesium-only product gives several times more per day.
Is this the same as magnesium B6?
It also contains vitamin B6, so you will find it in the magnesium with vitamin B6 category too. The difference is the potassium and the lower magnesium dose.
Can I take it with another magnesium supplement?
Add up the elemental magnesium from both products and stay within the daily dose stated on each label. If you are unsure, ask a pharmacist.
Why is the potassium dose only 300 mg?
Food is the main source of potassium, and the NRV is 2000 mg. Supplements usually add only a small share of that, and this tablet gives 15%.
Sources
- Regulation (EU) No 1169/2011, Annex XIII (reference intakes)
- Regulation (EU) No 432/2012 (permitted health claims)
- NIH Office of Dietary Supplements: Potassium fact sheet
- NIH Office of Dietary Supplements: Magnesium fact sheet
- EFSA: Health claims
Content reviewed by Inese Kalniņa, dietitian.
2026-10-08