Vitamin D Supplementation in TB Prevention

Vitamin D in TB Prevention in School Age Children

The goal of this clinical trial is to determine whether vitamin D supplementation reduces risk of acquiring latent tuberculosis infection (LTBI) in school age children in Mongolia. The investigators hypothesize that (1) vitamin D supplementation will reduce risk of acquisition of LTBI, (2) vitamin D supplementation will safely reduce risk of developing active TB and improve other secondary efficacy outcomes, and (3) children with the lowest vitamin D status at baseline will gain most from the intervention.

Inclusion Criteria:

1. Boys or girls aged 6 to 13 years at enrolment
2. Attending participating school in Ulaanbaatar at enrolment
3. Child gives informed assent to participate in the study
4. Child's parent/legal guardian gives informed consent for child to participate in study

Exclusion Criteria:

1. Chronic medical conditions
2. Presence of LTBI on screening, as evidenced by a positive QFT-G
3. Clinical signs of rickets, or diagnosis of any other condition requiring vitamin D supplementation
4. Known primary hyperparathyroidism or sarcoidosis
5. Taking immunosuppressant or cytotoxic therapy, or vitamin D supplement > 400IU / day
6. Plans to move away from study area within 3 years of enrolment