A patient with idiopathic hypoparathyroidism was resistant to the usual doses of ergocalciferol. She developed acute renal failure as a consequence of ureteral ligation with secondary renal parenchymal inflammation, and hypercalcemia was noted during the diuretic phase of renal failure. On complete recovery from that renal failure, she became sensitive to doses of ergocalciferol that had previously been ineffective.
The occurrence of hypercalcemia in this patient with hypoparathyroidism suggests that the hypercalcemia of acute renal failure may not necessarily be dependent on parathyroid hormone, and in some cases may be related to alterations in vitamin D metabolism or end-organ responsiveness.