The proposed study is a parallel, randomized, double-blinded, placebo-controlled clinical trial to quantify the change, if any, in microbiological outcome in TB patients treated with vitamin D in combination with standard DOTS therapy. It will take place in four South Indian DOTS centres. The required sample size is 250 patients receiving ATT, to be randomised in a 1:1 fashion (125 patients to receive vitamin D and 125 patients to receive placebo).