[Magnesium: physiological and clinical relevance. 1: homeostasis and alterations in the metabolism of magnesium].

Magnesium is the second most abundant cation in intracellular fluid and is an essential electrolyte. It has several critically important roles in the body, namely as a cofactor in numerous enzyme systems, and is involved in phosphate transfer, muscle contractility and neuronal transmission. The physiologic role, homeostasis, causes and clinical manifestations of hypo and hypermagnesemia and their therapy are briefly reviewed. Magnesium treatment is emerging as an important adjunct in the management of a few conditions: prevention and control of seizures in eclampsia, cardiovascular diseases, diabetes mellitus, asthma and others.