Research progress on the role of vitamin D in respiratory tract infection in children

Abstract

In recent years, vitamin D research has made important progress in non-skeletal health.Lack of vitamin D or deficiency can lead to the susceptibility of children with respiratory tract infection (RTI). RTIs are more likely to occur with serum 25 hydroxyl D [25(OH)D] concentrations <38 μg/L (95 nmol/L). Daily or weekly vitamin D supplementation has a protective effect on RTI.Vitamin D has a major impact on the immune system and directly or indirectly regulates more than 200 different genes by binding 1, 25 dihydroxy D[1, 25 (OH)2D] to the vitamin D receptor (VDR). Regulation of innate immunity causes downstream reactions to produce antimicrobial peptides, which lead to the killing of various pathogenic bacteria.In addition, regulation of adaptive immunity [helper T lymphocyte(Th)1, Th2, regulatory T cells(Treg) cells and Th17] and regulation of the inflammatory cascade by regulating the nuclear factor kappa B (NF-κB) pathway.These are good for prevention and treatment of children RTI.The recommended daily dose of vitamin D supplementation recommended by the American Medical Institute for bone health and the optimal 25(OH)D concentration for preventing and treating vitamin D supplementation in other non-bony iliac system diseases are also described.This article aims to further understand vitamin D and introduce its research progress in the prevention and treatment RTI in children. Key words: Vitamin D; Immune system; Respiratory tract infection; Effect; Child