title: Preliminary findings: 25(OH)D levels and PTH are indicators of rapid bone accrual in pubertal children.
abstract: OBJECTIVE
  The objective of this study was to evaluate the role of serum levels of 25(OH)D and PTH on the accumulation of whole body bone mass in a cohort of children.
  
  
  METHODS
  This was a longitudinal study (1.98 +/- 0.07 y) of sixty-nine children (89% Caucasian, 44% male) enrolled in a calcium supplementation trial. Bone area, bone mineral content (BMC) and density (BMD) of the whole body and radius were assessed using a QDR 2000 (Hologic, Inc) dual energy x-ray absorptiometer. Serum PTH and 25(OH)D were measured using radioimmunoassays.
  
  
  RESULTS
  Vitamin D stores were inversely related gain in bone area (p < 0.002), BMC (p < 0.002) BMD (p < 0.027), as well as to PTH levels (p < 0.0001). Compared to those with adequate vitamin D stores (>34 ng/ml), those who had consistently low vitamin D stores (18 ng/ml) had a 8% larger gain in bone area (p < 0.05); 11% in BMC (p < 0.05) and no differences in gain in BMD; after adjusting for baseline bone measurements, race, gender, season measured, Tanner stage, and calcium intake.
  
  
  CONCLUSIONS
  High normal PTH with low-normal 25(OH)D stores and moderate to high calcium intake may be beneficial to accruing larger bone size and BMC during puberty.
authors.affiliation: University of Tennessee Health Science Center, Memphis, Tennessee, USA. ftylavsky@utmem.edu
authors.forename: Frances A
authors.initials: FA
authors.lastname: Tylavsky
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Ryder
authors.forename: Rongling
authors.initials: R
authors.lastname: Li
authors.forename: Vicki
authors.initials: V
authors.lastname: Park
authors.forename: Catherine
authors.initials: C
authors.lastname: Womack
authors.forename: John
authors.initials: J
authors.lastname: Norwood
authors.forename: Laura D
authors.initials: LD
authors.lastname: Carbone
authors.forename: Sulin
authors.initials: S
authors.lastname: Cheng
mesh_terms: D015502:Absorptiometry, Photon; D000135:Acid Phosphatase / Q000378:metabolism; D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects* / Q000502:physiology; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001842:Bone and Bones / Q000378:metabolism*; D002136:Calcium, Dietary / Q000008:administration & dosage* / Q000494:pharmacology; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D011627:Puberty / Q000378:metabolism*; D011863:Radioimmunoassay; D018167:Receptors, Calcitriol / Q000378:metabolism; D012923:Social Class; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D000135:Acid Phosphatase