VITAMIN D-RESISTANT RICKETS: THE EFFECT OF CALCIUM INFUSION ON PHOSPHATE REABSORPTION *

Abstract

Dec. 1960. The effects of intravenous Ca infusions were studied in patients (age range of 7-53 years) with vitamin D-resistant rickets (15 mg Ca/kg of body weight over a 4 hr. period). Phosphate reabsorption was measured before, during, and after the infusion. The infusion of Ca resulted in a prompt increase of renal phosphate reabsorption. The changes in serum and urine phosphate incident to the Ca infusion were consistent with decreasing parathyroid function. These studies indicate that extrarenal factors can greatly alter phosphate reabsorption in vitamin D-resistant rickets and that impaired phosphate reabsorption characteristic of the disease is not exclusively related to an intrinsic tubular defect.