Obesity in childhood and adolescence is an important clinical and social problem in all countries, due to its extremely adverse long-term health effects. Vitamin D deficiency is extremely widespread in the world. Obesity and metabolic syndrome are often associated with vitamin D deficit. The role of vitamin D deficiency in obesity and metabolic syndrome in childhood is not well understood. Aims - to study the relationship of vitamin D deficiency and carbohydrate metabolism parameters in school children with obesity. Material and methods. The cross-sectional study included 71 patients of the Arkhangelsk Children's Clinical Hospital named after P.G. Vyhletsova (32 boys, 39 girls, aged 10 to 15 years, all children live in Arkhangelsk) with abdominal obesity. An anthropometric study was conducted: height (cm), body weight (kg), waist circumference (cm), body mass index (BMI). Serum 25(ОН)D level, fasting glycemia, insulin level and HOMA-IR index were assessed. Results. It has been revealed that 98,6% of children have vitamin D deficiency of varying severity. 25(OH)D level in severely obese children (BMI>3SDS) was significantly lower than in other obese children (BMI<3SDS): 12.8 [7.3-14.9] vs 13.5 [8.9-18.2] ng/ml, (p=0.039). In children with hyperglycemia and insulin resistance, 25(OH)D levels were significantly lower compared with those who had normal glycemic parameters and HOMA-IR index. Conclusions. The high prevalence of vitamin D deficiency in children and adolescents with overweight and obesity, progressing with increasing obesity severity, has been demonstrated. The association of glucose metabolism disorders with vitamin D deficiency has been shown.