New Advances in Clinical Aspects of Vitamin D : II. THE PATHOGENESIS OF SO-CALLED VITAMIN D REFRACTORY RICKETS FROM THE VIEWPOINT OF NEW INFORMATION ON THE METABOLISM AND ACTION OF VITAMIN D.

Abstract

Vitamin D dependency, primary hypophosphatemic rickets and renal osteodystrophy were studied on their pathogenesis by employing oral isotopic test of calcium absorption (Avioli et al., 1965). Patients with vitamin D dependency and renal insufficiency apparently indicated the existence of specific intestinal transport defect of calcium, suggesting that there might be any impairment in the convertion of vitamin D to the biologically important metabolites or any inhibition of their binding activity to the nuclear membrane, while patient with primary hypophosphatemic rickets showed normal intestinal absorption of calcium. However, the detailed mechanism remained unknown and further studies are required.