[Magnesium--pathophysiology and clinical aspects].

Magnesium is one of the most wide-spread elements in nature. It is the fourth major cation in the human body (after Ca, Na and K), and the second most abundant within the cells (after K). More than 300 enzymatic reactions depend on the presence of magnesium, especially concerning the generation and use of adenosine triphosphate. Magnesium level is controlled by the kidneys and gastrointestinal tract. It appears closely linked to calcium, potassium and sodium balance. The fundamental role played by magnesium in different biological systems has been recognized during recent years, and disorders of magnesium metabolism are now diagnosed and treated more often. There are several molecular and cellular actions of magnesium that explain clinical manifestations of magnesium deficiency or excess. Treatment of altered magnesium status depends on the clinical setting. Guidelines for therapy are given.