EFFECT OF PARATHYROIDECTOMY ON SERUM 1-ALPHA,25-DIHYDROXYVITAMIN-D AND INTESTINAL CALCIUM-ABSORPTION IN PRIMARY HYPER-PARATHYROIDISM

Serum concentration of lα,25-dihydroxyvitamin D [1,25(OH)2D] and intestinal absorption were measured before and after parathyroidectomy in 11 patients with primary hyperparathyroidism. Serum 1,25(OH)2D was high preoperatively (P < 0.001) and normal postoperatively. Ca absorption was elevated preoperatively (P < 0.001) and decreased significantly after parathyroidectomy (P < 0.001). However, 5 of 11 patients had a persistent hyperabsorption of Ca postoperatively, despite normal serum 1,25(OH)2D. The results suggest that factors other than 1,25(OH)2D contribute to the maintenance of high intestinal Ca absorption in hyperparathyroid patients in the postoperative state. © 1979 by The Endocrine Society.