Vitamin D supply, respiratory viral infections and persistent wheezing in children: how significant is the relationship?

Abstract

The review discusses the multifaceted effect of vitamin D on antiviral immunity, induction of antimicrobial peptides, functional activity of immunocompetent cells, autophagy processes, clearance of viruses and viral fragments. The relationship between vitamin D and allergic inflammatory cells, its modulating and tolerogenic potential is considered. The inhibitory effect of vitamin D on eosinophils, mast cells, the production of pro-inflammatory and proallergic mediators, and the synthesis of IgE has been shown. The protective role of vitamin D in the development of remodeling and hyperresponsiveness of the respiratory tract has been established by reducing the number of goblet cells, mucus hypersecretion, and the expression of metalloproteinases. The effects of vitamin D on the replication of respiratory viruses and experimental resistance to them through the induction of antimicrobial peptides and other mechanisms have been demonstrated. Data from clinical studies on the preventive effect of vitamin D on the incidence of respiratory infections and episodes of persistent wheezing in children are presented. Children with respiratory syncytial infection and vitamin D deficiency were more likely to require respiratory support and mechanical ventilation. The preventive role of vitamin D in the development of obstructive bronchitis in children and severe bronchiolitis in infants has been shown. It has been established that normal levels of 25(OH)D in the mother significantly reduce the risk of developing bronchial obstruction in the child. Alternative data that do not support a protective effect of vitamin D on respiratory morbidity and wheezing in children are discussed. Further monitoring studies that take into account geographic location and analysis of the dose of cholecalciferol used to assess its preventive role in the development of wheezing and bronchial asthma in children are advisable.