The results of treatment of twenty children with vitamin-D resistant rickets with massive daily doses of vitamin D have been presented. In these children we were unable to prevent the recurrence of deformities or to restore a normal growth pattern. This failure parallels the inability of this therapy to correct the low serum phosphorus without producing marked hypercalcemia and renal insufficiency. According to roentgenographic evidence, healing of the rickets can he induced by large doses of vitamin D, but cure of the disease cannot be achieved in this manner. Currently, we are continuing with massive doses of vitamin D and also bracing the extremities until the children are five or six years of age and can cooperate in taking vitamin D. The use of multiple osteotomies over an intramedullary nail may be helpful in reducing the recurrence of the deformities.

Data have been presented demonstrating that, during a calcium infusion, the renal tubules in patients with vitamin-D resistant rickets are capable of normal phosphate transport. It is therefore suggested that the low serum phosphorus and hyperphosphaturia characteristic of the disease are caused by extrarenal factors of which secondary hyperparathyroidism is the most important.