ABSTRACT
Patients with recurrent formation of urinary calculi composed of calcium oxalate and calcium phosphate present a stubborn and curious puzzle to the urologist. The typical subject is free of demonstrable metabolic disease such as hyperparathyroidism or tumor metastases in bone, has a normal serum calcium, uninfected urine, and normal renal function. In 1929 J. R. Hammarsten reported that magnesium can increase the solubility of calcium oxalate in vitro. Others have shown experimentally that magnesium decreases the incidence of calcium oxalate stone formation. The urinary excretions of magnesium and calcium are positively correlated; that is, for increasing values of urinary calcium, the urinary magnesium rises. Most stone formers have high urinary calcium excretion associated with a disproportionately low magnesium output. Prophylactic treatment with magnesium hydroxide was instituted in 56 of the 70 patients with renal stone disease who had previously been investigated with regard to their magnesium metabolism.
