| Abstract: | Abstract: Vitamin D metabolism was examined in cases of severe untreated obesity, in which serum concentrations of 25-hydroxy- (25-HD), 1,25-dihydroxy- (1,25-DHD), and 24,25-dihydroxy-vitamin D (24,25-DHD) were determined in 14 obese patients (13 females, 1 male; ages 19-49) before and after jejunoileal bypass. Preoperative median values of 25-HD and 24,25-DHD were significantly lower, and that of 1,25-DHD and immunoreactive parathyroid hormone (iPTH) were significantly higher, in the obese patients than in control subjects. All 3 vitamin D metabolites declined following bypass surgery, while serum iPTH and alkaline phosphatase levels increased (suggesting the possibility of a secondary hyperparathyroidism). The results indicate that vitamin D metabolism is slightly abnormal in obesity, with increased severe vitamin D metabolic disturbances following jejunoileal bypass surgery. (wz). |
