Objectives: The purpose of this study is to evaluate the effect of vitamin D3 and calcium supplementation on levels of sex hormone cortisol and inflammatory biomarkers Interleukin 10, high-sensitivity C-reactive protein (hsCRP), in women with postpartum depression. Design: This study is a randomized, double-blind controlled randomized trial with 8 weeks period. Setting and conduct: Eighty one patients with postpartum depression and serum vitamin D levels less than normal range, with consecutive sampling method, will be selected from the Health Center number 1, located in the west of the Ahvaz city. Edinburgh questionnaire will be used to evaluate clinical symptoms. In addition, the severity of anxiety will be examined by the Spielberger Questionnaire. Questionnaires at baseline and every 2 weeks for 8 weeks will be completed by the patients. Major Inclusion criteria: Score of 12 and above from Edinburgh questionnaire; a period range from 1 month until 6 months after child birth. Major Exclusion criteria: Vitamin D and calcium levels to normal or above normal range; chronic diseases. Intervention: The subjects will be divided into 3 groups based on randomized block design: group 1 will receive 50000 units vitamin D3, every 14 days and one calcium carbonate tablet (500 milligram, daily), group 2 will receive 50000 units vitamin D3, every 14 days and one calcium placebo (500 milligram, daily), group 3 (control group) will receive vitamin D3 placebo contains edible paraffin, every 14 days and calcium placebo (daily), for 8 week. Main outcome variables: Biochemical measurements include serum levels of inflammatory factors (Interleukin 10, hsCRP) and cortisol will be measured using ELISA assay.