Influence of vitamin D supplementation on bone mineral content, bone turnover markers, and fracture risk in South African schoolchildren: multicenter double-blind randomized placebo-controlled trial (ViDiKids)

source extracted confidence: high 2026-04-09
#child #humans #bone-density #bone-remodeling #calcifediol

Influence of vitamin D supplementation on bone mineral content, bone turnover markers, and fracture risk in South African schoolchildren: multicenter double-blind randomized placebo-controlled trial (ViDiKids)

Middelkoop et al., 2024 | J Bone Miner Res | Rct

Citation

Middelkoop Keren, Micklesfield Lisa K, ... Martineau Adrian R. Influence of vitamin D supplementation on bone mineral content, bone turnover markers, and fracture risk in South African schoolchildren: multicenter double-blind randomized placebo-controlled trial (ViDiKids). J Bone Miner Res. 2024-Apr-19;39(3):211-221. doi:10.1093/jbmr/zjae007

Abstract

Randomized controlled trials (RCTs) to determine the influence of vitamin D on BMC and fracture risk in children of Black African ancestry are lacking. We conducted a sub-study (n = 450) nested within a phase 3 RCT of weekly oral supplementation with 10 000 IU vitamin D3 vs placebo for 3 yr in HIV-uninfected Cape Town schoolchildren aged 6-11 yr. Outcomes were BMC at the whole body less head (WBLH) and LS and serum 25-hydroxyvitamin D3 (25(OH)D3), PTH, alkaline phosphatase, C-terminal telopeptide, and PINP. Incidence of fractures was a secondary outcome of the main trial (n = 1682). At baseline, mean serum 25(OH)D3 concentration was 70.0 nmol/L (SD 13.5), and 5.8% of participants had serum 25(OH)D3 concentrations <50 nmol/L. Among sub-study participants, end-trial serum 25(OH)D3 concentrations were higher for participants allocated to vitamin D vs placebo (adjusted mean difference [aMD] 39.9 nmol/L, 95% CI, 36.1 to 43.6) and serum PTH concentrations were lower (aMD -0.55 pmol/L, 95% CI, -0.94 to -0.17). However, no interarm differences were seen for WBLH BMC (aMD -8.0 g, 95% CI, -30.7 to 14.7) or LS BMC (aMD -0.3 g, 95% CI, -1.3 to 0.8) or serum concentrations of bone turnover markers. Fractures were rare among participants in the main trial randomized to vitamin D vs placebo (7/755 vs 10/758 attending at least 1 follow-up; adjusted odds ratio 0.70, 95% CI, 0.27 to 1.85). In conclusion, a 3-yr course of weekly oral vitamin D supplementation elevated serum 25(OH)D3 concentrations and suppressed serum PTH concentrations in HIV-uninfected South African schoolchildren of Black African ancestry but did not influence BMC or serum concentrations of bone turnover markers. Fracture incidence was low, limiting power to detect an effect of vitamin D on this outcome.

Key Findings

Fracture incidence was low, limiting power to detect an effect of vitamin D on this outcome.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 450
Age Range aged 6-11
Condition See abstract

MeSH Terms

  • Child
  • Humans
  • Bone Density
  • Bone Remodeling
  • Calcifediol
  • Cholecalciferol
  • Dietary Supplements
  • Double-Blind Method
  • Fractures, Bone
  • HIV Infections
  • Randomized Controlled Trials as Topic
  • South Africa
  • Vitamin D
  • Vitamin D Deficiency
  • Black People
  • Southern African People

Evidence Classification

  • Level: Rct
  • Publication Types: Clinical Trial, Phase II, Journal Article, Multicenter Study, Randomized Controlled Trial
  • Vertical: vitamin-d-bone

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09