Magnesium supplementation in Gitelman syndrome.

The metabolism of potassium and magnesium are closely linked (in situations where potassium and magnesium depletion coexist, magnesium restoration alone is sufficient to correct hypokalemia). Moreover, magnesium deficiency blunts the interplay between circulating calcium and the calciotropic hormones. Renal magnesium wasting, hypokalemia, alkalosis, hypocalciuria, and a tendency towards hypocalcemia characterize Gitelman syndrome. Plasma or intracellular potassium, circulating calcium, and calciotropic hormones were therefore investigated in eight patients (4 females, 4 males, aged 9-20 years) with Gitelman syndrome before and during oral supplementation with magnesium pyrrolidone carboxylate 30 mmol daily for 4 weeks. Magnesium supplementation significantly increased plasma and intracellular magnesium and plasma calcium, but failed to completely restore magnesium deficiency. In contrast, blood levels of parathyroid hormone and calcitriol and plasma and intracellular potassium were not modified following magnesium administration.