Renal magnesium excretion is no marker for magnesium deficiency

Background: Serum magnesium analysis does not reflect body content of magne sium. So substitution is based on empirical maneuvers. Patients and Method: In a study on 44 patients urinary magnesium excretion was analyzed before and after oral magnesium substitution (40 mval). The pr ovable hypothesis was the estimation that patients in magnesium deficiency under; chronical diuretic treatment (n = 11) would have a lower magnesium e xcretion than patients of the control soup (n = 10). Further analysis ts as done with patients after orthotopic cardiac transplantation (n = 12) and t hose suffering from coronary heart disease (n = 11). Result: After oral administration of magnesium in all 4 soups there was a r ise in blood levels, only significant in the patient group under chronic di uretic treatment; Urinary magnesium excretion, however, showed no significa nt differences. Patients after cardiac transplantation had the lowest rise in urinary magnesium excretion. Conclusion: There was no clear differentiation by means of this oral magnes ium substitution test. Magnesium excretion even after oral substitution of no value to analyze magnesium deficiency.