Prevalence of Vitamin D deficiency in the North-West region of Russia: A cross-sectional study

Russia is a country with geographic and economic preconditions for development of vitamin D deficiency. We analyzed serum 25(OH)D level in residents from North-West region (59-61° North latitude) of Russia to study the prevalence of vitamin D insufficiency and deficiency and its associations with gender, age, obesity and diet. The study population included 1664 residents (1544 adults 18-75 y.o. and 120 children/adolescents of 3-17 y.o.). Serum 25(OH)D was determined in 1226 participants by electrochemiluminescence immunoassay. We used a questionnaire to check the frequency of dairy and fish products intake as well as the use of vitamin supplements. The serum 25(OH)D level was 9.8-147.5nmol/L, mean level in adults population was 54.8±0.7nMol/L, in children/adolescents-46.8±1.6 nmol/L. We revealed that 16.8% of the study population had a 25(OH)D level more than 75nMol/L, 37.5% had insufficiency and 45.7% had vitamin D deficiency. Serum 25(OH)D level in women was lower than in men (53.9±0.8 and 67.2±2.2nmol/L; p