Background: Vitamin D deficiency remains the most common cause of rickets globally and is highly prevalent in developing countries including India. This study aimed to compare the efficacy of vitamin D and calcium together with calcium alone on growth parameters of children with vitamin D deficiency in community based setting.Methods: A randomized controlled trial was conducted in community based setting in Kanpur district. Multistage random sampling technique was used to select a total of 395 children between 2 years to 5 years from 5 villages of block Vidhunu. Of these, 138 children were randomized into two groups using balanced block randomization technique. Group 1 received vitamin D with calcium together and group 2 received calcium alone for a period of 12 months. Anthropometry, serum vitamin D, calcium, alkaline phosphatase levels were estimated at baseline and after 12 months. Data was analyzed using SPSS 20. Student’s t test was used to analyze the differences in growth and laboratory parameters in the two groups. Multiple linear regression analysis was used to assess the effect of various factors on the growth parameters.Results: Prevalence of vitamin D deficiency was 78.7%. Baseline characteristics of both groups were similar. After 12 months, group 1 demonstrated significantly greater improvement in weight SD score (21.4%) and height SD score (10.3%) and growth velocity (9.1 cm/year) compared to group 2 (14.3%, 7.8% and 6.9 cm/ year respectively). Also subjects in group 1 showed significantly greater improvement in serum levels of vitamin D, calcium and alkaline phosphatase than group 2.Conclusions: Vitamin D supplementation along with calcium improves the growth of children. Regular supplementation of all children with vitamin D can be considered as a policy for prevention of malnutrition.