Hypercalcemia in an Anephric Patient with Sarcoidosis: Evidence for Extrarenal Generation of 1,25-Dihydroxyvitamin D

HYPERCALCEMIA can occur in up to 10 per cent of patients with sarcoidosis.1 , 2 During the active phase of the disease, increased absorption of calcium from the intestine leads to hypercalciuria and occasionally hypercalcemia. The increased absorption of calcium is presumed to be secondary to increased sensitivity to vitamin D,3 and it may be decreased or abolished by the development of concomitant renal failure.4 Recent reports have identified elevated circulating levels of 1,25-dihydroxyvitamin D (1,25-[OH]2D) in hypercalcemic patients with sarcoidosis, and it has been suggested that such patients produce increased amounts of 1,25-(OH)2D3 from vitamin D. . . .