Bone Health, Body Composition, and Vitamin D Status of Black Preadolescent Children in South Africa

Nutrients. 2019 May 31;11(6):1243. doi: 10.3390/nu11061243.

Abstract

Optimal bone health is important in children to reduce the risk of osteoporosis later in life. Both body composition and vitamin D play an important role in bone health. This study aimed to describe bone health, body composition, and vitamin D status, and the relationship between these among a group of conveniently sampled black preadolescent South African children (n = 84) using a cross-sectional study. Body composition, bone mineral density (BMD), and bone mineral content (BMC) were assessed using dual x-ray absorptiometry. Levels of 25-hydroxyvitamin D (25(OH)D) (n = 59) were assessed using dried blood spots. A quarter (25%) of children presented with low bone mass density for their chronological age (BMD Z-score < -2) and 7% with low BMC-for-age (BMC Z-score < -2), while only 34% of the children had sufficient vitamin D status (25(OH)D ≥ 30 ng/mL). Lean mass was the greatest body compositional determinant for variances observed in bone health measures. Body composition and bone health parameters were not significantly different across vitamin D status groups (p > 0.05), except for lumbar spine bone mineral apparent density (LS-BMAD) (p < 0.01). No association was found between bone parameters at all sites and levels of 25(OH)D (p > 0.05). Further research, using larger representative samples of South African children including all race groups is needed before any conclusions and subsequent recommendation among this population group can be made.

Keywords: South Africa; body composition; bone health; preadolescent children; vitamin D.

MeSH terms

  • Black People*
  • Body Composition*
  • Bone Density / physiology*
  • Child
  • Cross-Sectional Studies
  • Female
  • Humans
  • Logistic Models
  • Male
  • South Africa
  • Vitamin D Deficiency / epidemiology*