Relationship between vitamin D status, rs2228570 vitamin D receptor polymorphism genotypes, and cholecalciferol supplementation in school-age children with COVID-19

Purpose - to study the features of vitamin D status and the effect of vitamin D3 supplementation on 25(OH)D in the serum of school-age children with COVID-19, taking into account the genotype of the rs2228570 polymorphism of the vitamin D receptor (VDR) gene. Materials and methods. The pilot, prospective, open-label study included 36 schoolchildren aged 9-16 who experienced asymptomatic (12 children) and mild / moderate (24 children) COVID-19. In all children were studied the content of 25(OH)D in blood serum and its dynamics under the influence of supplementation of 1000 IU per day for 12 weeks, taking into account the genotypes and frequency of distribution of alleles of the rs2228570 polymorphism of the VDR gene (26 children). Results. Children with asymptomatic COVID-19 were characterized by normal values of 25(OH)D (32.682.12 ng/ml). Children who underwent mild / moderate COVID-19 were probably more (41.7%) likely to have a state of hypovitaminosis vitamin D (27.362.12 ng/ml) and fewer children (58.3%) with an optimal level of 25(OH)D than children with asymptomatic disease. In 80.7% of the examined children, the genotype was determined by the rs2228570 polymorphism of the VDR gene, which includes the G allele with greater transcriptional activity of the VDR receptor. Supplementation of 1000 IU of cholecalciferol per day, regardless of 25(OH)D status and genotype for this polymorphism probably increased the supply of vitamin D in examined children with a tendency to increase 25(OH)D in children with genotype by polymorphism rs2228570 VDR gene, which includes allele G. Conclusions. Vitamin D deficiency can be considered as a risk factor for the symptomatic course of COVID-19 in children, which requires monitoring and correction of vitamin D status, the effectiveness of which can be determined by the genotype of the rs2228570 polymorphism of the VDR gene. Further studies of the role of vitamin D / VDR complex in the development and severity of COVID-19 in children will significantly expand the understanding of the pathogenetic relationship, to suggest and predict the effectiveness of personalized vitamin D supplementation regimens. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of all participating institutions. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.