title: Pubertal changes in calcium kinetics in girls assessed using 42Ca.
abstract: The rate of calcium deposition in bone (Vo+) and the size of the exchangeable calcium pool in bone (EP) were measured in 50 girls aged 4.9 to 16.7 y using i.v. administered 42Ca. Both Vo+ and EP reached a maximum during early puberty and decreased in late puberty and more than 2 y postmenarche. In contrast, the initial mass of calcium distribution did not decrease in late puberty. The ratio of calcium deposition in bone to the exchangeable pool size, i.e. ko+ = Vo+/EP, was more closely correlated with length of time since menarche (r = 0.83, p < 0.001) than with age (r = 0.65, p < 0.001), weight (r = 0.51, p < 0.001), or body mass index (r = 0.28, p = 0.05). The lower ko+ in late puberty indicates that as bone matures the fraction of the calcium pool that enters bone decreases.
authors.affiliation: Department of Pediatrics, USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: S A
authors.initials: SA
authors.lastname: Abrams
mesh_terms: D000293:Adolescent; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002127:Calcium Isotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008572:Menarche / Q000378:metabolism; D011627:Puberty / Q000378:metabolism*
chemical_list: D002127:Calcium Isotopes; D002118:Calcium