To assess the clinical outcome of oral Vitamin D3 Supplementation in Type 2 Diabetes Mellitus patients with generalised chronic adult Periodontitis. A total of 92 subjects, comprising 46 in non diabetic and 46 in diabetic group were enrolled in the clinical trial according to the inclusion and exclusion criteria. Periodontal clinical parameter, Probing Pocket Depth (PPD) was assessed at baseline. Following initial examination Scaling and root planing was completed for all the subjects enrolled in the study and by cluster randomization first 25 subject subjects from each group were supplemented with oral vitamin D3 granules of 60,000IU once a week for 8 weeks following SRP. At the end of the study after 8 weeks, Probing Pocket Depth was reassessed. Significant improvement was seen in both interventions namely SRP +VITAMIN D and SRP alone .But marked reduction in PPD was seen in SRP+vitamin D supplemented group. Reduction in PPD was more for Non diabetic subjects when compared to Diabetic subjects. Vitamin D supplementation can be used as an adjunct to SRP for both diabetic and non diabetic patients with chronic periodontitis in vitamin D deficient subjects.