[The significance of magnesium in medicine. (I) Biological function, homeostasis, ingestion and excretion (author's transl)].

Magnesium (Mg) has numerous biological functions, one of the most important being its role in the metabolism of ATP. In addition it is a significant structural element in DNA and membranes. Parathormone and metabolites of vitamin D affect Mg homeostasis. The intestinal absorption depends principally on the amount and availability of the Mg in the diet. The Mg content of the organism is effectively regulated on the other hand by adaptation of the renal excretion.