title: Side-chain hydroxylation of vitamin D3 and its physiological implications.
abstract: Evidence is accumulating that, in vivo and in vitro, both 25-OH-D3 and 1,25-(OH)2D3 undergo side-chain modification leading to side-chain cleaved metabolites lacking the 24, 25, 26, and 27 carbons. The enzymes involved are D-dependent and are located in the kidney, bone, intestine, and perhaps other sites. We speculate that the extra-renal side-chain pathway may be primarily for target organ destruction of 1,25-(OH)2D3, whereas the renal pathway may be primarily for destruction of 25-OH-D3 formed in large amounts in hypervitaminosis D.
authors.affiliation: Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Jones
authors.forename: D
authors.initials: D
authors.lastname: Vriezen
authors.forename: D
authors.initials: D
authors.lastname: Lohnes
authors.forename: V
authors.initials: V
authors.lastname: Palda
authors.forename: N S
authors.initials: NS
authors.lastname: Edwards
mesh_terms: D000818:Animals; D002762:Cholecalciferol / Q000378:metabolism* / Q000502:physiology; D006900:Hydroxylation; D007668:Kidney / Q000378:metabolism; D051381:Rats
chemical_list: D002762:Cholecalciferol