Definition of Vitamin D3
Vitamin D3: A vitamin produced by the body when exposed to ultraviolet light or obtained from dietary sources. Vitamin D3 is a hormone that has an important role in calcium and phosphorus metabolism. Technically, vitamin D3 is not a vitamin because the body can produce it. Also known as cholecalciferol.
Last Editorial Review: 5/13/2016
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?