BackgroundType 2 diabetes mellitus (T2DM) is one of the most common non-communicable diseases, causing a high mortality rate globally. Vitamin D deficiency has been reported as a rising pandemic. Vitamin D levels have been found to be associated with obesity and insulin resistance. However, there is not much research done to study the various factors associated with the association between vitamin D levels and diabetes mellitus in the Indian population.ObjectiveThe objective of this study is to estimate the prevalence of vitamin D deficiency in T2DM patients and find the factors associated with vitamin D levels among type 2 diabetes mellitus patients.Materials and methodsA cross-sectional analytical study was planned and done in the Urban Health Training Centre of Dr. D.Y. Patil Medical College. The sample size was calculated using published data on prevalence. Data from 116 T2DM patients were collected using a questionnaire about their socio-economic status, dietary patterns, outdoor activities, exercise, drug and supplement intake, occupation, and symptoms, which was filled out by the participants after written informed consent. Levels of serum vitamin D were estimated from the blood samples taken from the participants. Statistical analysis was done using MedCalc software.ResultsVitamin D deficiency was found in 86 (74.14%) out of 116 diabetic patients. There were 63 males, and 71.43% of them had lower-than-normal vitamin D levels. The number of female participants was 53, and 77.36% were found to suffer from vitamin D deficiency. There were 88 obese participants, and only 22.73% were found to have sufficient levels of vitamin D.ConclusionThe results depict a high prevalence of vitamin D deficiency in type 2 diabetes mellitus patients. Regular supplementation of vitamin D for diabetic patients can prevent them from developing any further complications. Increasing awareness about a healthy lifestyle, a proper diet, adequate sunlight, and exercise can help keep most non-communicable diseases at bay. Additional studies should be done to understand the pathophysiology better, which can aid in preventing diseases in the beginning stages of development.