Vitamin D is a major determinant of bone mineral density at school age

PLoS One. 2012;7(7):e40090. doi: 10.1371/journal.pone.0040090. Epub 2012 Jul 2.

Abstract

Background: Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption, bone mineralization and bone mass attainment.

Methodology/principal findings: This school-based study investigated vitamin D status and its association with vitamin D intake and bone health in 195 Finnish children and adolescents (age range 7-19 years). Clinical characteristics, physical activity and dietary vitamin D intake were evaluated. Blood and urine samples were collected for serum 25-hydroxyvitamin D (25-OHD) and other parameters of calcium homeostasis. Bone mineral density (BMD) and body composition were measured with dual-energy X-ray absorptiometry (DXA). Altogether 71% of the subjects were vitamin D insufficient (25-OHD <50 nmol/L). The median 25-OHD was 41 nmol/L for girls and 45 nmol/L for boys, and the respective median vitamin D intakes 9.1 µg/day and 10 µg/day. In regression analysis, after adjusting for relevant factors, 25-OHD concentration explained 5.6% of the variance in lumbar BMD; 25-OHD and exercise together explained 7.6% of the variance in total hip BMD and 17% of the variance in whole body BMD. S-25-OHD was an independent determinant of lumbar spine and whole body BMD and in magnitude surpassed the effects of physical activity.

Conclusions/significance: Vitamin D insufficiency was common even when vitamin D intake exceeded the recommended daily intake. Vitamin D status was a key determinant of BMD. The findings suggest urgent need to increase vitamin D intake to optimize bone health in children.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adolescent
  • Adult
  • Bone Density*
  • Calcium / metabolism
  • Child
  • Female
  • Finland
  • Humans
  • Male
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood
  • Vitamin D / urine
  • Vitamin D Deficiency / blood*
  • Vitamin D Deficiency / urine*

Substances

  • Vitamin D
  • 25-hydroxyvitamin D
  • Calcium