Magnesium is vital for so many bodily processes that it's difficult to corral them all and there's a lot of debate online about which is the best form to supplement with.
Magnesium oxide is not as easy to render soluble as some other magnesium salts.
It’s therefore not absorbed as rapidly as other forms of magnesium, e.g. citrate, gluconate, lactate and aspartate.
But although magnesium oxide has a lower rate of absorption it contains a MUCH greater amount of actual magnesium to begin with.
More than that provided by other magnesium salts.
Therefore, even with the lower rate of absorption, magnesium oxide still delivers more magnesium per capsule.
So more magnesium gets into your bloodstream to deliver all its many benefits to your bones and body.
Because magnesium oxide contains more elemental magnesium and is less soluble, it’s absorbed into the bloodstream more slowly as it passes through the digestive tract.
It will not raise blood levels excessively, and will therefore not be rapidly excreted.