Background: Over the past decade, interest has grown in the role of vitamin D in many nonskeletal medical conditions, such as cancer, diabetes mellitus, and cardiovascular diseases including respiratory infection. Emerging evidence indicates that vitamin D-mediated innate immunity is important in host defenses against respiratory tract pathogens. There are few researches linking vitamin D to various immune-related conditions, including asthma, allergic rhinitis, although the pattern of this relationship is still yet to establish. This study was done to understand the role of vitamin D levels in patients with respiratory tract infection in the southern part of India. Materials and Methods: After obtaining ethical clearance from the institutional ethics committee retrospective study was conducted. A total of 125 Patients with respiratory complaints like bronchial asthma, chronic obstructive pulmonary disease, and allergic rhinitis were included.100 healthy volunteers were included as a control. Total serum vitamin D assay was measured by ECLIA method. Serum IgE levels were measured using COBAS 6001 analyzer. Statistical analysis was done using SPSS 16.0 version. Results: Vitamin D level was highly significantly lower(p __ampersandsignlt;0.01) in the respiratory diseases group compared with the control group, and the total IgE level was highly significantly higher in the asthmatic groups compared with the control group. Conclusion: Deficiency of Vitamin D levels may predispose to respiratory infections. Supplementation with vitamin D, exposure to sun light and increased physical activity may decrease the predisposition to respiratory tract infection.