[Clinical significance of magnesium. 1: Distribution in the organism, evaluation of current supply].

The most important compartments of Mg metabolism are described: Bone Mg stores correlate closely with serum Mg, which latter depends mainly on intestinal absorption and excretion, predominantly via the kidneys. Since intracellular Mg is mainly bound, the overall intracellular Mg concentration depends largely on the amount of available ligands such as ATP. Serum Mg reflects the Mg content of bone stores. The frequency at which hyper- or hypomagnesemia occurs depends largely on the precision with which the normal range is established. Recommendations for the sampling of serum are made.