Correlation between bone magnesium concentration and magnesium retention in the intravenous magnesium load test.

It has been suspected that Mg retained in the Mg load test is retained in bone--in both hypomagnesaemic and normomagnesaemic Mg deficiency. Bone Mg concentration was therefore compared to the percentage retention of an intravenously administered load of Mg in normomagnesaemic patients at high risk for Mg deficit. We found that the lower the bone Mg concentration the higher the Mg retention in the Mg load test.