I’m not sure. I know the bioavailability of magnesium citrate is much better than that of magnesium oxide, due to the bad solubility in water of the latter (and

I’m not sure. I know the bioavailability of magnesium citrate is much better than that of magnesium oxide, due to the bad solubility in water of the latter (and supplements with magnesium oxide are thus next to useless). That suggests Mg ions already present should be readily absorbed.