title: Biological activity of a polar metabolite of vitamin D.
mesh_terms: D000818:Animals; D001681:Biological Assay; D002118:Calcium / Q000378:metabolism; D002127:Calcium Isotopes; D002247:Carbon Isotopes; D002645:Chickens; D002762:Cholecalciferol / Q000097:blood / Q000378:metabolism*; D007408:Intestinal Absorption; D014316:Tritium
chemical_list: D002127:Calcium Isotopes; D002247:Carbon Isotopes; D014316:Tritium; D002762:Cholecalciferol; D002118:Calcium