The Role of the Vitamin D Endocrine System in Health and Disease

Abstract

The secosteroid hormone 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) is the major biologically active metabolite of vitamin D3. (Secosteroids are those in which one of the rings has undergone fission; in vitamin D, this is ring B.) 1,25(OH)2D3 is recognized as the principal mediator within the sphere of action of vitamin D in the regulation of bone and mineral metabolism in humans.1 2 3 Recent evidence has suggested a wider biologic role of 1,25(OH)2D3 in tissues not primarily related to mineral metabolism.Vitamin D MetabolismMetabolic ActivationAn overview of vitamin D . . .