Magnesium Studies in Relation to Hyperparathyroidism

IN THE clinical study of hyperparathyroidism there have been few contributions concerning the metabolism of magnesium. The studies of Bulger and Gausmann (1), Bassett and Alstine (2, 3), and Tibbetts and Aub (4) are confirmed and extended here in relation to a patient requiring two operations for the removal of a hyperfunctioning parathyroid tumor. In view of the chemical similarity of magnesium and calcium it might be supposed that these elements are both affected in hyperparathyroidism. In order to obtain further information on magnesium metabolism in this disorder a balance study was conducted in a case of hyperparathyroidism, prior to and following extirpation of an active parathyroid tumor. The results of this study, as well as pertinent background for their interpretation, arc considered here. Previous balance studies on healthy subjects (4–9) revealed three main difficulties: 1) Magnesium intakes are more than adequate, and this obscures minor physiologic alterations in the metabolism of magnesium. The adult requirement for magnesium has not been established or confirmed (10–14). In a recent review (15) it was said to be less than 10 mg. or 0.83 mEq. per day during growth. Presumably the requirement is less in adult life, and is far exceeded in magnesium balance studies.