[Provision of vitamin D in the adult population of Western Siberia: a population-based study].

The results of research in recent years indicate a widespread low intake of vitamin D, its deficiency or lack among the population of many countries around the world. It is of interest to study vitamin D status of the population living at different geographic latitudes and depending on socio-demographic characteristics. The aim of the research is to analyze vitamin D status of the adult population living in the Omsk Region over the age of 18 in different seasons of the year. Material and methods. Evaluation of vitamin D status has been carried out in 818 adult residents (325 men and 493 women) aged 18 to 92 years, the median of age - 49 (35; 63) years. Vitamin D status was determined by the level of [25 (OH) D] in serum by the method of immuno-chemiluminescent or electrochemiluminescent analysis. Design: cross-section (simultaneous) uncontrolled epidemiological study. Research period: 2017, from January to December. Results and discussion. 25.8±1.5% showed optimal vitamin D provision, insufficient vitamin content was found in 32.5±1.6% of studied participants, and deficit in 41.4±1.7%. The median level of 25(OH)D for all subjects was in the suboptimal sufficiency range and amounted to 22.17 (16.5; 30.3) ng/ml. The lowest level of the metabolite has been registered in patients over the age of 80 years - 16.5 (13.2-22.6) ng/ml, at the age of 70-79 years - 19.1 (12.9-26.9) ng/ml. In persons aged 18-60 years, the median concentrations were higher (22.2-24.8 ng/ml) and did not differ in the age groups. Deficiencies of varying degrees were most prevalent in age groups over 80, 70-79, and 50-59 years. Slightly better sufficiency of men compared with women has been revealed (p=0.052). Seasonal differences were found in the nature of vitamin D supply characterized by a deficit state from January to June [median 18.7 (13.9; 23.5) ng/ml] and a state of insufficiency from July to December [median 24.8 (17.8; 32.04) ng/ml]. The dependence of the level of vitamin D status on the number of sunshine days during the periods of 15-90 days preceding blood collection hasn't been established. Conclusion. The problem of insufficiency of vitamin D applies to all age groups of the adult population of the region of Western Siberia, especially those over 70 years of age. For the first half of the year, predominantly deficient states are characteristic, and for the period from July to December - the state of vitamin D insufficiency in the residents.