title: Vitamin D endocrine physiology.
abstract: Quantitative aspects of vitamin D(3) endocrine physiology are briefly reviewed, together with the supporting evidence. Net calcium absorption of at least 200 mg/d is required to offset typical obligatory losses and thereby to protect the skeleton. The ability of the body to regulate intestinal calcium absorption is optimal at serum 25-hydroxyvitamin D(3) concentrations >80 nM. Vitamin D(3) inputs from all sources required to sustain such a level amount to 3600-4200 IU/d. Daily oral intakes as high as 10,000 IU are safe.
authors.affiliation: Creighton University, Omaha, Nebraska, USA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Heaney
mesh_terms: D000042:Absorption; D002118:Calcium / Q000378:metabolism; D004703:Endocrine System / Q000502:physiology*; D006801:Humans; D010281:Parathyroid Hormone / Q000378:metabolism; D014807:Vitamin D / Q000009:adverse effects / Q000378:metabolism*; D014808:Vitamin D Deficiency / Q000378:metabolism
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002118:Calcium