[Tubular and intestinal phosphate transport in vitamin D-resistant (hypophosphatemic) rickets (author's transl)].

Renal clearance and intestinal absorption studies were performed to investigate the renal and intestinal handling of phosphate under various conditions in two female patients with VDRR. The two types of transepithelial phosphate transport in the renal proximal tubule and intestinal mucosa are discussed. The defective parathormone sensible transport mechanism is slightly depressed under the influence of parathormone and activated after treatment of vitamin D in one patient, in the other no further inhibition by PTH could be observed. Electrolyte excretion in urine remains stable during treatment with vitamin D 3. Therapy consists of administration of oral phosphate and of pharmacologic doses of vitamin D.