The Kidney as an Endocrine Organ for the Production of 1,25-Dihydroxyvitamin D3, a Calcium-Mobilizing Hormone

Abstract

THE classic effect of vitamin D is to bring about mineralization of bone. Although the possibility remains that some form of vitamin D functions directly at the mineralization site, most evidence indicates that vitamin D acts by supplying calcium and phosphate to the calcification sites. Thus, the extracellular fluid in vitamin D deficiency is undersaturated with the hydroxyapatite-mineral component of bone, and it is this factor that is thought to have the major role in the failure of calcification in this deficiency disease.¹ It is generally believed that the vitamin brings about an elevation of plasma calcium and phosphorus by . . .