Influence of vitamin D supplementation on growth, body composition, pubertal development and spirometry in South African schoolchildren: A randomised controlled trial (ViDiKids)

Keren Middelkoop, Lisa Micklesfield, Justine Stewart, Neil Walker, David A. Jolliffe, Amy E. Mendham, Anna K. Coussens, James Nuttall, Jonathan Tang, William D. Fraser, Waheedullah Momand, Cyrus Cooper, Nicholas C. Harvey, Robert J. Wilkinson, Linda-Gail Bekker, Adrian R. Martineau (Lead Author)

Research output: Contribution to journalArticlepeer-review


Objective: To determine whether weekly oral vitamin D supplementation influences growth, body composition, pubertal development or spirometric outcomes in South African schoolchildren.
Design: Phase 3 double-blind randomised placebo-controlled trial ( registration no. NCT02880982).
Setting: Socio-economically disadvantaged peri-urban district of Cape Town, South Africa.
Participants: 1682 children of Black African ancestry attending government primary schools and aged 6-11 years at baseline.
Interventions: Oral vitamin D3 (10,000 IU/week) vs. placebo for 3 years.
Main outcome measures: height-for-age and body mass index-for-age, measured in all participants); Tanner scores for pubertal development, spirometric lung volumes and body composition, measured in a subset of 450 children who additionally took part in a nested sub-study.
Results: Mean serum 25-hydroxyvitamin D3 concentration at 3-year follow-up was higher among children randomised to receive vitamin D vs. placebo (104.3 vs. 64.7 nmol/L, respectively; mean difference [MD] 39.7 nmol/L, 95% CI 37.6 to 41.9 nmol/L). No statistically significant differences in height-for-age z-score (adjusted MD [aMD] -0.08, 95% CI -0.19 to 0.03) or body mass index-for-age z-score (aMD -0.04, 95% CI -0.16 to 0.07) were seen between vitamin D vs. placebo groups at follow-up. Among sub-study participants, allocation to vitamin D vs. placebo did not influence pubertal development scores, % predicted forced expiratory volume in 1 second (FEV1), % predicted forced vital capacity (FVC), % predicted FEV1/FVC, fat mass or fat-free mass.
Conclusions: Weekly oral administration of 10,000 IU vitamin D3 boosted vitamin D status but did not influence growth, body composition, pubertal development or spirometric outcomes in South African schoolchildren.
Original languageEnglish
JournalBMJ Paediatrics Open
Issue number1
Publication statusPublished - 10 Apr 2024

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