Cholecalciferol as a means of nonspecific immunoprophylaxis against COVID-19

The current direction of scientific research in recent years has been the study of the immunobiological properties of vitamin D. The purpose of this work was to analyze the results of oral administration of cholecalciferol in order to prevent infection with the SARS-CoV-2 virus in the first wave of the COVID-19 pandemic. The study was performed in the period from October 07 to December 29, 2020, when there were no immunobiological drugs for specific prevention of COVID-19. The total number of respondents was 73 people; all had been ill with coronavirus only once. The etiological diagnosis of the disease included molecular genetic testing of samples of two localizations obtained by the conventional method (nasopharynx, oropharynx). The concentration of antibodies to the virus was determined on average 2 months after the disease using a set of reagents SARS-CoV-2-IgG quantitative-ELISA-Best (JSC Vector-Best, Russia). An approximate assessment of IgM concentration was carried out using a set of SARS-CoV-2-IgM-ELISA-Best from the same manufacturer. Among the study participants were those who used immunobiological drugs for the prevention of infection (riamilovir, umifenovir hydrochloride monohydrate, human recombinant interferon alpha-2b, zinc acetate, vitamin C). In particular, 28 people (38.4%) took cholecalciferol (group No. 1) and 45 people (61.6%) did not use this (group No. 2). Statistical processing of the obtained data was performed using the statistical package STATISTICA v.12.5.192.5 (StatSoft, Inc., USA). We applied the analysis of basic statistics, Linear Discriminant Analysis, Kolmogorov–Smirnov test, Chi-Square test, Wald–Wolfowitz Runs Test, Kruskal– Wallis test. Differences in the incidence of respiratory distress syndrome of the two studied groups were revealed: in patients taking cholecalciferol, the syndrome did not develop at all; in group No. 2, it was registered in 20.0% of cases (Chi-Square = 5.242, p = 0.02). In addition, in patients of group No. 1, the concentration of IgG 2 months after the disease was 3.8 times higher than the values in group No. 2 (Chi-Square = 9.268, p = 0.003). Similar differences were found for the IgM level (Wilks' Lambda: 0.659 approx. F (7.32) = 2.367 p < 0.045). It was known that in both groups there were respondents who used other immuno-active substances for preventive purposes. In the first group there were 18 people (24.7% of all); in the second, there were 13 people (17.8% of all). It was found that thos