Vitamin D supplementation to prevent tuberculosis infection in South African schoolchildren: multicenter phase 3 double-blind randomized placebo-controlled trial (ViDiKids)

•We did a phase 3 randomized placebo-controlled trial of vitamin D to prevent tuberculosis (TB) infection in 1682 QuantiFERON-TB Plus-negative children in Cape Town, South Africa.•In total, 63.2% of participants had serum 25-hydroxyvitamin D (25[OH]D) concentrations <75 nmol/l at baseline.•The intervention was weekly oral administration of 10,000 IU vitamin D3 for 3 years.•This was effective in elevating serum 25(OH)D concentrations in participants randomized to the intervention arm of the trial.•The intervention did not influence the risk of QuantiFERON-TB Plus conversion.