Tuberculosis (TB)is one of the top 10 causes of death worldwide and the leading cause of death from a single infectious agent (ranking above HIV/AIDS). In 2019, globally about 10 million people developed tuberculosis and 1.4 million died. About a quarter of the world’s population is infected with M. tuberculosis.  India is the highest TB burden country in the world having an estimated incidence of 26.9 lakh cases in 2019 (WHO).

 Hypovitaminosis D is associated with more severe clinical symptoms, a higher degree of sputum smear positivity and more extensive lesions in chest radiograph among pulmonary tuberculosis patients. Also, low serum Vitamin D level is a good predictor of prolonged clinical course (poor treatment outcome) in patients with active pulmonary TB.    

 Vitamin D is an immunomodulator agent. Vitamin D (1,25 (OH)2D) mediates antimicrobial activity via induction of reactive oxygen intermediates, reactive nitrogen intermediates, antimicrobial peptides (Cathelecidin) and Autophagy. Vitamin D regulate the Adaptive Immune System by inhibiting Lymphocyte proliferation and reducing production of pro-inflammatory cytokines to prevent excessive response. Thus, the ability of 1,25(OH)₂D to promote antibacterial activity while simultaneously modulating T-cell function underlines the potential importance of Vitamin D in maintaining a balanced immune response to infection, while minimizing tissue damage within the host.     

Therefore to evaluate the effect of vitamin D supplementation on the outcome of pulmonary TB patient we assessed the effect of vitamin D supplementation on following variables DLC, ESR, serum ADA, serum CRP, oxygen saturation (SpO2) and body weight in vitamin D deficient newly diagnosed pulmonary TB patients. For this, we  conducted a prospective interventional randomized double blind parallel group active controlled clinical trial. After randomization, we allocated the study participants in two groups, the control group (received standard ATT without vitamin D3   supplementation) and intervention  group (received standard ATT with vitamin D3 supplementation). At the time of enrollment of participants we measured baseline characteristics including study variables. During follow-up measurement of all the study variables and monitoring of any adverse events was carried out. Statistical analysis of all data obtained from participants was analyzed using SPSS software.