Introduction: Drug Resistant Tuberculosis (DR-TB) is a rapidly escalating problem. Vitamin D and calcium serum levels can be an important determinant of Multidrug-Resistant Tuberculosis (MDR-TB) infection, progression to disease.The link between the serum level of 25-hydroxy vitamin-D {25(OH) D and MDR-TB is an emerging area for conducting evidencebased research. Aim: To assess the serum 25(OH)D and calcium levels and its deficiency in all the patients with drug resistant tuberculosis. Materials and Methods: This retrospective, observational study was conducted in the Department of Pulmonary Medicine, Indira Gandhi Institute of Medical Sciences, Patna, Bihar, India, from October 2019 to October 2020, in the newly detected 100 patients experiencing DR-TB. Patients sputum/body fluid samples were subjected for GeneXpert/Line Probe Assay (LPA) examinations to confirm resistance to anti-tubercular drugs. The frequency and prevalence of mean serum vitamin D and mean serum calcium levels were recorded based on age and gender. DR-TB categorised into H-Mono resistance, MDR-TB, Pre-Extensively Drug Resistant (Pre-XDR) and XDR-PTB, based on GeneXpert and LPA of sputum/body fluid. Descriptive statistics were used to determine the characteristics of all the patients. All the statistical analysis was done using the STATA software. Results: Mean age of study population was 31.12±15.49 years. Among them 63 were males and 37 were females. The mean serum vitamin D level of 10.87±8.49 ng/mL (deficient) and serum calcium level of 8.62±0.82 mg/dL (normal) was reported. Mean serum vitamin D levels were deficient in all the four types of DR-TB (p-value=0.04), while changes in mean serum calcium level was non significant (p-value=0.15). Conclusion: All patients with DR-TB have significant propensity to vitamin D deficiency. While changes in mean serum calcium level was non significant.