[Immunoreactive parathyroid hormone, 25-hydroxycalciferol and bone histology in renal osteodystrophy (author's transl)].

Immunoreactive parathyroid hormone (iPTH) and 25-hydroxycalciferol (25(OH)D) serum levels were determined in 32 patients with renal osteopathy, they were correlated with the results of bone biopsy and other clinical parameters. iPTH was closely related to bone histology, it did not correspond to serum calcium and alkaline phosphatase, but the correlation to serum phosphate was statistically significant. 25(OH)D levels were not related to the histological findings of osteomalacia or increased bone resorption, while a correlation between the vitamin D metabolite and serum calcium could be observed. Since iPTH and 25(OH)D levels exhibited a significant correlation, an inhibitory effect of 25(OH)D on parathyroid gland function in renal failure was discussed.