EFFECTS OF VITAMIN-D3 ON MINERAL METABOLISM IN PATIENTS WITH CHRONIC-RENAL-FAILURE AND IN DIALYSIS PATIENTS

In chronic renal failure, deficiency of activated vitamin D metabolites leads to reduced intestinal calcium absorption, resulting in a negative calcium balance and secondary hyperparathyroidism, which are the causes for uremic osteopathy, a condition fraught with grave consequences. The parameters of mineral metabolism were determined in 9 patients with chronic renal failure and 11 dialysis patients before and after a 6-month treatment with 0.5 mg/d vitamin D3. Total calcium and the ionized calcium fraction normalized under this therapy. This effect ran parallel to a distinct rise of the 25-hydroxycholecalciferol level. Parathyroid hormone secretion, however, could not be influenced, while the retention of phosphates increased at the same time. Alkaline phosphatase and collagen peptidase activity increased during therapy, as did the excretion of hydroxyproline. Hypocalcemia can be corrected by administration of vitamin D3 preparations, but regular surveillance of therapy is required.