- In this randomized clinical trial (RCT), high-dose vitamin D supplementation failed to prevent tuberculosis (TB) infection and disease in schoolchildren.
Why this matters
- The rationale for the first RCT of its kind was that vitamin D metabolites support innate immune responses to the Mycobacterium tuberculosis that causes TB.
- Findings do not support vitamin D supplementation for TB prevention.
- RCT (N=8851) in which schoolchildren without latent TB infection in Mongolia were given oral weekly placebo or 14,000 IU of vitamin D3 over the course of 3 years.
- Primary outcome was onset of latent TB infection, as shown by conversion to a positive result on the QuantiFERON-TB Gold In-Tube (QFT) assay.
- Funding: NIH.
- No difference between groups at 3 years on conversion to a positive result on QFT assay indicating latent TB infection:
- Adjusted risk ratio (aRR): 1.10 (P=.42).
- The vitamin D group (vs placebo) had higher serum mean 25-hydroxyvitamin D level (31.0 vs 10.7 ng/mL).
- Mean between-group difference, 20.3 (95% CI, 19.9-20.6) ng/mL.
- No differences between groups for:
- TB disease: aRR, 0.87 (95% CI, 0.49-1.55).
- Hospitalization for treatment of acute respiratory infection: aRR, 0.86 (95% CI, 0.52-1.40).
- Incidence of adverse events.
- RCT may have been underpowered to detect primary outcome.