Vitamin D Status Among Residents of the Russian Federation and Its Relation with Age and Parathyroid Hormone

Abstract

Objective: to study the vitamin D (25(OH)D) status in various regions of the Russian Federation (RF), and to determine the relation between age, levels of 25(OH)D and parathyroid hormone (PTH).Methods: The vitamin D status was investigated in residents of various regions of the Russian Federation (Northwestern Federal District, Central Federal District, Southern Federal District and Far Eastern Federal District) between 2012 and 2017. In this cross-sectional study 115694 anonymous samples were analyzed. All samples were provided by an independent commercial laboratory. Serum levels of vitamin D (25(OH)D) were measured using chemiluminescent assay.Results: The prevalence of low levels of 25(OH)D was widespread in the Russian Federation: deficiency (0,05). The median level of vitamin D was higher in the summertime than in the winter months (25,3 ng/ml [18,3; 33,5] vs 24 ng/ml [16,7; 32,5], p=0,006). Levels of 25(OH)D30 ng/ml) was low, which was comparable to the age group over 80 years (22,6 % and 18 %, respectively, p=0,1). A negative inverse correlation between vitamin D and PTH levels was confirmed (r=-0,11, p=0,002). There was a weak positive correlation between the age of participants and PTH levels (r=0,18, p=0,000).Conclusion: The obtained data indicate the high prevalence of 25(OH)D deficiency among all age groups in the Russian Federation. Vitamin D levels were statistically differed depending on age and season. Geographic factors did not have a significant impact on vitamin D status in different regions of the Russian Federation. The highest prevalence of severe D deficiency was observed in age group younger 20 years and over 80 years. A weak positive correlation was established between age and PTH levels. Considering the high frequency of low vitamin D concentrations in the elderly age group, this condition rеrequires adequate correction and further follow-up in order to prevent the negative effects of vitamin D deficiency on bones.