Bile calcification Alcohol (English: Cholecalciferol, also known as vitamin D3 or bile calcification) is a kind of vitamin D, cholesterol after the formation of 7-dehydrogenase cholesterol through ultraviolet irradiation can form bile calcification alcohol, so that is the bile calcification of the vitamin D is 7-dehydrogenation cholesterol. Bile calcification alcohols in the liver by the hydroxylation of the role of the formation of 25-hydroxy gall bladder calcification, and then in the kidneys were 1,25-two hydroxy bile calcium alcohol, the activity of the substance than gallbladder calcification 50% high, proved to be vitamin D in the body's real active form. And 1,25-Two is a hormone secreted by the kidneys, so it is actually a hormone.