[Causes and treatment of hypomagnesemia].

Plasma magnesium (Mg) is known to be maintained within a normal range through its gastrointestinal absorption as well as renal excretion, and disturbances at these sites might cause hypomagnesemia. Mg balance is most susceptible to the malfunction of the thick ascending limb of renal tubules, because 70% of urinary Mg excretion is reabsorbed from this site. Investigation of hypomagnesemia-exhibiting inherited diseases revealed molecular mechanisms of Mg transport pathways; paracellin-1 as a passive paracellular transport and TRPM6 as an active transcellular transport. Mild and severe hypomagnesemia are treated with oral replacement such as magnesium oxide, as well as intravenous administration of magnesium sulfate.