Hypothesis

That improving vitamin D status among TB patients will speed the pace of bacteriological cure, and will enhance immune responses to TB infection

Tuberculosis (TB) will be the world's largest single cause of death from infection for the 30-year period between 1990 and 2020. More than 95% of TB cases, and deaths due to TB, occur in developing countries. Mongolia is one of the countries with the highest tuberculosis burdens in the Western Pacific region. In addition, vitamin D deficiency is endemic in Mongolia. We propose to determine the efficacy of vitamin D supplements, as an adjunct to multidrug therapy, in enhancing the anti-microbial immune response to TB, a finding that could lead to the development of shorter drug regimens, and thus more efficient and effective TB treatment protocols.

We propose to conduct a double blind, placebo controlled, randomized clinical trial to test the effect of a daily vitamin D supplementation on the ability of subjects to control TB infection.

The Primary Endpoint: The primary endpoint will be: time to sputum culture conversion from positive to negative. The number of days to sputum conversion will be measured, in both the intervention and control groups, starting on the date that treatment is begun. Sputum samples will be collected and cultured every two weeks thereafter. The date of conversion from positive to negative, for each subject, will be the date halfway between the date of the last culture-positive sputum and the first culture-negative one.

Secondary Endpoints:

Bacteriologic secondary endpoints, cell-mediated immune function endpoints and BMI.

Inclusion Criteria:

• Sputum positive TB patients

Exclusion Criteria:

• We will exclude those with abnormal LFTs at baseline (2.5 times upper limit of normal), as they will be at higher risk of developing drug-induced hepatitis