MTBs- stimulated IFN-g levels are increased post-therapy in TB patients with deficient Vitamin D levels. Whole blood cells were stimulated with MTBs and IFN-g measured in cell supernatants at 6 days post-stimulation. Vitamin D levels >30 ng/ml, Optimal; 20–30 ng/ml, Insufficient; <20 ng/nl, Deficient. a, Placebo arm b, Drug intervention arm. The box and whiskers plots depict cytokine responses in the 10th to 90th percentiles with the horizontal bar indicating the median levels of each group. ‘*' Denotes p <0.05 between levels at 0 and 12 weeks respectively as determined by paired t test analysis.