No effect of vitamin D supplementation on TB prevention in schoolchildren

  • Ganmaa D & al.
  • N Engl J Med
  • 23 Jul 2020

  • curated by Miriam Davis, PhD
  • Clinical Essentials
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Takeaway

  • 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.

Study design

  • 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.

Key results

  • 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.

Limitations

  • RCT may have been underpowered to detect primary outcome.