Objective of this study is evaluation of effectiveness of oral administration of vitamin D in anemia of patients with type 2 diabetes with mild renal impairment. This study is a Phase II clinical trial, triple blind, single-center study. All patients with type 2 diabetes and anemia (Hb <12 for females and Hb,13 for males) who were referred to Imam Ali hospital clinics and their serum vitamin D levels are lower than 30 ng / ml are considered. The patients in stage 1 renal impairment with normal serum iron, ferritin, retic, LDH, ESR, TIBC, erythropoietin and unexplained anemia, after applying exclusion criteria are included. All participants provided informed consent. Patients were randomly assigned in two groups ( 50 patients in case group and 50 patients in control group). In case group, patients receiving vitamin D 50000 unit per week for 8 weeks and in control group patients receiving placebo for 8 weeks Finally, the hemoglobin, hematocrit levels and vitamin D for each patient was recorded at the end of the second month of treatment and outcomes of the two groups will be compared.