In a randomized controlled trial, a daily Oral Vitamin D supplementation was given in dose of 2000 IU for Group A, 1000 IU for Group B , 500 IU for Group C and placebo for Group D over 3 months period to assess the anti-inflammatory effect of vitamin D on gingivitis at various doses. The changes in gingival scores were measured at the period of 1 st , 2 nd and 3 rd month. Gingivitis score changed in direct proportion to the dose of vitamin D supplementation. Group A mean gingival scores were 2.4 (baseline); 1.7 (1 st month), 0.8 (2 nd month) and 0.3 (3 rd month). The group B the mean baseline gingival score from 2.3 reduced to 2.0 (month), 1.1 (two months) and 0.5 (third month). Group C had baseline gingival scores of 2.2 and 1.9 (1 st month), 1.4 (2 nd month) and 0.8 (last visit). Comparing baseline gingivitis scores with later visit score by Wilcoxon paired test, the anti-inflammatory effect was significantly seen in group A after one month itself, group B at two months and group C at 3 rd month after oral vitamin D supplementation. However, Group D did not show any significant anti-inflammatory effect.