Osteoporosis International

, Volume 21, Issue 4, pp 695–700

Vitamin D status and parathyroid hormone relationship in adolescents and its association with bone health parameters: analysis of the Northern Ireland Young Heart’s Project

  • T. R. Hill
  • A. A. Cotter
  • S. Mitchell
  • C. A. Boreham
  • W. Dubitzky
  • L. Murray
  • J. J. Strain
  • A. Flynn
  • P. J. Robson
  • J. M. W. Wallace
  • M. Kiely
  • K. D. Cashman
Short Communication

DOI: 10.1007/s00198-009-0959-1

Cite this article as:
Hill, T.R., Cotter, A.A., Mitchell, S. et al. Osteoporos Int (2010) 21: 695. doi:10.1007/s00198-009-0959-1

Abstract

Summary

In girls, a plateau in parathyroid hormone (PTH) was observed at a 25-hydroxyvitamin D (25(OH)D) concentration of approximately 60 nmol/l. In boys, there was no plateau in PTH concentrations as 25(OH)D concentration increased. A 25(OH)D threshold of 60 nmol/l appears to have implications for bone health outcomes in both girls and boys.

Introduction

Our objective was to investigate if there is a threshold 25(OH)D concentration where a plateau in PTH concentration is evident and to examine the impact of this relationship on bone mineral density (BMD) and bone turnover in a representative sample of adolescents.

Methods

We conducted a cross-sectional analysis among 1,015 Northern Irish adolescents aged 12 and 15 years. Serum 25(OH)D, PTH, osteocalcin, type 1 collagen cross-linked C-telopeptide (CTx), and BMD of the nondominant forearm and heel were measured. Nonlinear regression analysis was used to model the association between 25(OH)D and PTH.

Results

In girls, a plateau in PTH was observed at a 25(OH)D concentration of approximately 60 nmol/l (PTH = 47.146 + 370.314 × exp(−0.092 × 25(OH)D)) while no plateau in PTH was observed in boys (PTH = 42.144 + 56.366 × exp(−0.022 × 25(OH)D)). Subjects with 25(OH)D levels <60 nmol/l had significantly higher osteocalcin concentrations (P < 0.05) compared with those who had ≥60 nmol/l, while no significant (P > 0.05) differences were noted for CTx concentrations. In girls only, nondominant forearm BMD but not heel BMD was significantly higher (P = 0.046) in those with 25(OH)D concentrations ≥ 60 nmol/l.

Conclusions

Serum 25(OH)D levels above 60 nmol/l in Northern Irish adolescent girls prevent an increase in serum PTH levels and maintaining 25(OH)D >60 nmol/l in both girls and boys may lead to improved bone health outcomes.

Keywords

AdolescentsBone turnoverPTHVitamin D

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2009

Authors and Affiliations

  • T. R. Hill
    • 1
  • A. A. Cotter
    • 1
  • S. Mitchell
    • 1
  • C. A. Boreham
    • 5
  • W. Dubitzky
    • 3
  • L. Murray
    • 6
  • J. J. Strain
    • 3
  • A. Flynn
    • 1
  • P. J. Robson
    • 4
  • J. M. W. Wallace
    • 3
  • M. Kiely
    • 1
  • K. D. Cashman
    • 1
    • 2
  1. 1.Vitamin D Research Group, Department of Food and Nutritional SciencesUniversity CollegeCorkIreland
  2. 2.Department of MedicineUniversity CollegeCorkIreland
  3. 3.Northern Ireland Center for Food and HealthUniversity of UlsterColeraineUK
  4. 4.Department of Population Health Research Alberta Health Services - Cancer Epidemiology, Prevention and Screening Sun Life PlaceEdmontonCanada
  5. 5.UCD Institute for Sport and HealthUniversity CollegeDublinIreland
  6. 6.Department of Epidemiology and Public HealthQueens UniversityBelfastUK