Vitamin D is known to regulate many cellular functions such as insulin secretion, cardiac function, immune system, skeletal muscle in addition to bone mineral metabolism. With respect to diabetes, diabetes prevention trials by vitamin D supplementation and reports showing an association between low levels of blood vitamin D and cardiovascular events, bone fractures, falls and most recently the life prognosis have been published. However, reports on Japanese diabetic patients and vitamin D is scarce. We measured serum 25 (OH) D concentration (ECLIA) in 133 patients (M/F: 85/48) with type 1 (n=15) and type 2 diabetes patients (118). Age, sex, BMI and biochemical indicators (serum Ca, P, Alb, HbA1c, LDL-C, TG, CPR and atherosclerosis indices (urinary albumin, NT-proBNP, baPWV and max IMT) were investigated. The subjects mean age was 59.1±14.0 years (mean±SD) and HbA1c9.1 ±2.6%, and BMI25.0±4.3. Serum 25 (OH) D concentration state was only 3% in sufficient group(>30ng/ml), 11% insufficient group and 86% was in deficiency (<20ng/ml). This was the same regardless of type 1 or type 2. Correlations with the aforementioned indicators including HbA1c was not observed. However, serum 25 (OH) D concentration and max IMT in HbA1c above 8% group had a weak but significant reverse correlation, which was consistent with the previous metaanalysis. The limitation of this study is a single center based, and it does not include data on dieting status, or exposure to sunlight. However, subjects have a history of medical nutritional education and they are residents of urban areas with adequate ADL, it is unlikely that they are particularly biased diabetes populations. In an aging society, it is important to prevent sarcopenia, and fractures in diabetes. The present results shed a new insight in Japanese medical nutritional therapy. For vitamin D deficiency cohort, interventions and bone salt quantification are going to be carried out and osteoporosis, fractures, and cardiovascular risk are evaluated in a prospective manner. Disclosure N. Kashima: None. K. Hamano: None.