Objective. To identify the relationship between the serum vitamin B content and the polymorphism of the vitamin B receptor gene with the severity of the course of COVID-19-associated lung damage.To identify the relationship between serum vitamin D content and polymorphism of the vitamin D receptor gene with the severity of COVID-19- associated lung damage. Materials and methods. The paper presents the results of an examination of 200 people, after 1 month suffering COVID-associated lung damage in the period from June 1 to October 31, 2020. The patients were divided into groups of 50 people depending on the degree of lung damage based on the results of computed tomography: group 1 (CT-1), median by age was 51.5 [50.5; 54.8]; group 2 (CT-2), median by age 57.0 [53.1; 57.0]; group 3 (CT-3), median by age 52.5 [51.9; 55.0]; group 4 (CT-4), median 55.0 [53.2; 56.4]. The control group included 56 relatively healthy people who did not have coronavirus infection; the median age was 55.0 [51.1; 55.0]. All groups were comparable in age and gender. The concentration of total 25-hydroxyvitamin D (25(OH)D) was studied in blood serum. A molecular genetic study of the vitamin D receptor gene was also carried out: 283 A>G (BsmI) and 2 A>G (FokI). Results. It was revealed that insufficient levels of 25(OH)D in the blood are one of the risk factors for the development of COVID-19 infection, as well as a risk factor for worsening the course of COVID-19-associated lung damage. Analysis of the polymorphism of the vitamin D receptor gene VDR: 283 A>G showed the predominant inheritance of allele A and homozygote A/A in patients with a high level of damage to lung tissue due to COVID-19 infection — KT-3, 4. Study of polymorphism of the vitamin D receptor gene VDR: 2 A>G showed preferential inheritance of homozygote A/A among patients compared to the control group. When studying the concentration of vitamin D in patients with COVID-19-associated lung damage depending on the polymorphism of the vitamin D receptor genes VDR: 283 A>G (BsmI) and VDR: 2 A>G (FokI), no differences were found. Conclusion. Insufficient levels of 25(OH)D in the blood may be one of the factors contributing to the complicated course of coronavirus infection. Analysis of the vitamin D receptor gene polymorphism VDR: 283 A>G showed preferential inheritance of the A allele and homozygote A/A in a more severe category of patients — with more than 50 % damage to the lung tissue (CT-3, 4) against the background of COVID-19 infection. A study of the polymorphism of the vitamin D receptor gene VDR: 2 A>G revealed the most common carriage of the A/A homozygote among patients compared to the control group.
