The Effect of Oral Phosphate in Patients With Recurrent Renal Calculus

SUMMARY The administration of disodium hydrogen phosphate dihydrate (12 g. daily) to male patients with recurrent calcium‐containing renal stones resulted in an increased urinary excretion of orthophosphate, pyrophosphate, and citrate and a decreased excretion of calcium and magnesium. The decrease in urine calcium and magnesium was accompanied by an increase in fascal calcium and magnesium but the change in the fasces was less marked than in the urine and the net effect was a more positive calcium and magnesium balance. Favourable results were observed in eighteen patients with frequently recurring calculi who received orthophosphate for periods varying up to two years. In two other cases, however, there was radiological evidence of new stone formation. The changes in urine composition resulting from phosphate supplementation and deprivation are discussed in relation to their effect on the “crystallising propensity” of urine.