Abstract : Pulmonary Tuberculosis (PTB) is a chronic infectious disease caused by Mycobacterium tuberculosis. Vitamin D3 is a secosteroid that has pleiotropic effects on many organs, including the adaptive immune system and the innate immune system. It is a potent immunomodulator of innate immune responses by acting as a cofactor for induction of anti-mycobacterial activity [6]. Vitamin D3 deficiency is generally prevalent in pulmonary tuberculosis patients. Hence, we extended our study to analyze the changes in the level of vitamin D3 in various subgroups of PTB patients which includes newly diagnosed sputum positive PTB; Recurrent PTB; PTB in patients with Diabetes mellitus and PTB patients who lost to follow up. A cross-sectional study was conducted among 95 sputum positive pulmonary tuberculosis patients over a period of two years in Department of Pulmonary Medicine, SMVMCH, India. Serum Vitamin D3 levels were measured in the study subjects and their levels were compared among the different subgroups. Vitamin D3 deficiency (<10ng/ml) was found in all the subgroups of pulmonary tuberculosis patients with higher prevalence in patients with advanced age, low BMI, farmers, smokers, alcoholics and diabetes. However, difference in Vitamin D3 levels among the patients with newly diagnosed PTB, Recurrent TB and PTB who lost follow up were not statistically significant. Hence, vitamin D3 level has to be assessed in all the pulmonary tuberculosis patients and supplementation of vitamin D3 in patients with deficiency and insufficiency improves the morbidity in these groups of patients.