title: 1,25-dihydroxycholecalciferol: identification of the proposed active form of vitamin D3 in the intestine.
abstract: The major polar metabolite of cholecalciferol (vitamin D(3)) present in chick intestinal mucosa has been chemically characterized by mass spectrometric analysis to have a molecular formula of C(27)H(44)0(3) and a structure of 1,25-dihydroxycholecalciferol. This compound, which is produced in the kidney from 25-hydroxycholecalciferol, has been previously shown to be from 4 to 13 times as active as cholecalciferol in stimulating intestinal calcium transport. 1,25-Dihydroxycholecalciferol (previously designated metabolite 4B in this (laboratory) probably represents the biologically active form of cholecalciferol in the intestine.
mesh_terms: D000367:Age Factors; D000818:Animals; D002625:Chemistry, Organic; D002645:Chickens; D002762:Cholecalciferol / Q000032:analysis* / Q000378:metabolism; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000032:analysis* / Q000378:metabolism; D007668:Kidney / Q000032:analysis / Q000378:metabolism; D013058:Mass Spectrometry; D008970:Molecular Weight; D055601:Organic Chemistry Phenomena; D014808:Vitamin D Deficiency / Q000378:metabolism
chemical_list: D002762:Cholecalciferol