Abstract: Objective   To explore the effect of vitamin D2 (VD2) on type 2 diabetic cardiac autonomic neuropathy (DCAN) in different medication cycles. Methods  200 DCAN patients were randomly divided into the control group and the treatment group B1B3, both groups were given conventional treatment. The treatment group was given intramuscular injection of VD2 according to body weight,  5000 IU/kg each time,  once every 2 weeks. According to different medication cycle plans,  they were divided into three groups: B1,  B2,  and B3,  and the medication time was 3 months,  6 months,  and 1 year respectively. One year after treatment was the clinical end point. The efficiency was observed,  and the concentration of 25hydroxyvitamin D(25［OH］D) and heart rate variability (HRV) index were observed before,  at the end of treatment and one year after the end of treatment. Results  At the end of treatment and one year later,  the efficiency of the 1year group was higher than that of the 3month and 6month groups,  the VD deficiency rate was lower than that of the 3month and 6month groups,  and the heart rate variability index and 25 (OH) D level were better than those of the 3month and 6month groups (P<0.05). Conclusion  VD deficiency is common in DCAN patients. VD2 is effective for DCAN,  and can improve  VD nutritional status and HRV indexes of patients. The curative effect of longterm treatment is better than that of shortterm treatment.

Key words: diabetes, type 2, cardiac autonomic neuropathy, vitamin D