title: Oral calcium suppresses biochemical markers of bone resorption in normal men.
abstract: Calcium supplementation decreases bone resorption and retards bone loss in women. There is little information about the effects of calcium supplementation in men. The effects of a 1-g oral calcium load at 0900 on bone-related biochemical variables were evaluated in 13 normal men (aged 51-70 y). Calcium administration was associated with increases in plasma ionized calcium (P < 0.001) and urinary calcium (P < 0.001), and a decrease in plasma parathyroid hormone (P < 0.001). There was a nonsignificant trend (r = -0.47, P = 0.11) for the decrease in plasma parathyroid hormone to be related to radiocalcium absorption. After the calcium load there were decreases in the urinary hydroxyproline-creatinine ratio from 11 +/- 1.1 to 7.9 +/- 0.6 (P < 0.01), the urinary deoxypyridinoline-creatinine ratio from 14.0 +/- 1.8 to 10.1 +/- 0.9 (P < 0.05), and the urinary pyridinoline-creatinine ratio from 52 +/- 5 to 40 +/- 3 (P < 0.01) between baseline and 6 h. There was no change in plasma osteocalcin. These observations indicate that a 1-g calcium load suppresses biochemical markers of bone resorption for > or = 6 h in normal men and support the concept that calcium supplementation may be useful in the prevention of bone loss in men.
authors.affiliation: Department of Medicine, Royal Adelaide Hospital, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Horowitz
authors.forename: J M
authors.initials: JM
authors.lastname: Wishart
authors.forename: D
authors.initials: D
authors.lastname: Goh
authors.forename: H A
authors.initials: HA
authors.lastname: Morris
authors.forename: A G
authors.initials: AG
authors.lastname: Need
authors.forename: B E
authors.initials: BE
authors.lastname: Nordin
mesh_terms: D000042:Absorption; D000328:Adult; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers; D001862:Bone Resorption; D002118:Calcium / Q000008:administration & dosage / Q000494:pharmacology* / Q000652:urine; D002132:Calcium Radioisotopes; D003404:Creatinine / Q000652:urine; D006801:Humans; D006909:Hydroxyproline / Q000652:urine; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D002132:Calcium Radioisotopes; D010281:Parathyroid Hormone; C015484:pyridinoline; C036020:deoxypyridinoline; D003404:Creatinine; D006909:Hydroxyproline; D002118:Calcium