There are still no FDA approved drugs for NAFLD so far. Vitamin D may be a good therapeutic option for NAFLD patients due to its insulin sensitizing and anti-inflammatory properties. The purpose is to investigate the effect of oral vitamin D supplementation on various parameters in NAFLD patients. In this double blind randomized placebo controlled trial, 109 patients of NAFLD diagnosed by abdominal ultrasound and liver enzymes were divided into two groups for treatment with oral capsule of vitamin D3 50,000 IU and capsule placebo weekly for a period of 12 weeks. Anthropometric, chemical, metabolic and inflammatory parameters were assessed pre and post treatment by using SPSS 16. After 12 weeks oral treatment with vitamin D , its level increased significantly in vitamin D group from 12.5±4.2 to 24.5±3.8 ng/ml p =0.003 vs placebo group. This rise was further accompanied by decrease in HOMA-IR (4.56±1.6 to 3.26± 1.8 p=0.003) liver enzymes (i.e. ALT: 72.±17.6 to 54.5±14.5 IU/L p=0.04; AST: 68±14.5 to 46.± 10.5 p =0.002) serum CRP 3.25±0.68 to 2.28±0.44 mg/L p =0.06 and increase in serum adiponectin 8.56 ±1.12 to 10.44±2.35 mg/L p =0.03 as compared to placebo group. However non significant changes were observed in both groups in terms of body weight, BMI, and serum lipid profiles. Vitamin D supplementation not only improved its own status but also caused a significant amelioration in metabolic, chemical and inflammatory parameters in NAFLD patients. So it should be consider as an adjunctive therapy in NAFLD patients.