Impact of compliance with cholecalciferol administration on the incidence of respiratory infections in young children

Abstract

Introduction. Data on the vitamin D receptors (VDR) found on the surface of a large number of cell types of the human body were first published several decades ago, which served as a prerequisite to study the role of vitamin D in the development of some diseases, including infections.Objective of the study.Evaluate the relationship between administration of cholecalciferol supplements, the synthesis of defensins, and the incidence and morbidity patterns of acute respiratory infections (ARI) in young children.Material and methods.108 healthy children aged 1 month to 3 years were examined, of which 34 (31.5%) were vitamin D sufficient, 40 (37.0%) had a vitamin D insufficiency, 27 (25.0%) had a vitamin D deficiency and 7 (6.5%) children had severe vitamin D deficiency. After the course of treatment of vitamin D deficiency with therapeutic doses, all patients were prescribed prophylactic doses of cholecalciferol supplements (1000 IU/day) for a 6-month course.Results. Therapeutic doses of cholecalciferol promoted β1 and β2-defensin expression; a direct correlation was found between the daily dose of vitamin D and the increase of β2-defensin expression (r = 0.34, p <0.05). Administration of cholecalciferol in the prophylactic dose of 1000 IU/day for 6 months was accompanied by the further increase in antimicrobial peptide (AMP) production, which resulted in the increase of the β1-defensin level by 2.4 times (p <0.001) and β2-defensin level by 2.5 times (p <0.001) as compared with the baseline levels. The incidence of respiratory morbidity amounted to 1.7 ± 0.2 episodes every 6 months against the background of ongoing cholecalciferol supplementation. The number of patients, who were not infected, was significantly more in the group of children with optimal vitamin D status, than in the groups of children with vitamin D insufficiency and deficiency.Conclusions. Administration of vitamin D supplements induces antimicrobial peptide expression and reduces the frequency and severity of acute respiratory infections in young children.

Keywords

• vitamin d
• antimicrobial peptides
• morbidity
• acute respiratory infections
• children