Vitamin D receptor polymorphisms as predictors of pediatric infectious disease prevalence and outcome: an overview of available evidence.

BACKGROUND AND OBJECTIVE: Polymorphisms of the vitamin D receptor (VDR) gene have been studied in relation to various diseases, including infections. This narrative review aims to summarize the role of VDR polymorphisms in the susceptibility towards pediatric infectious diseases, as well as in their complications. METHODS: We conducted a narrative review of the available literature data (PubMed/MEDLINE, Web of Science and Google Scholar databases) published until January 31st, 2026. Search keywords included "VDR" AND "child" AND "respiratory tract infection" OR "gastroenteritis" OR "diarrhea" OR "urinary tract infection". RESULTS: A total number of 21 studies complied to the inclusion and exclusion criteria. FokI remains the most intensely studied polymorphism of the VDR gene in relation to pediatric infections and its genotypes are differentially expressed in relation to infections of the respiratory tract requiring hospitalization. There are no studies available analyzing the impact of VDR gene polymorphisms in acute infectious diarrhea, but two studies have shown so far that children who are carriers of particular genotypes of the ApaI, FokI and/or BsmI polymorphisms are more predisposed towards developing urinary tract infections. Data on pediatric/neonatal sepsis is scarce, limited to three studies which have shown inconsistent, contradictory findings. CONCLUSIONS: Future studies are warranted to validate or infirm the role of VDR gene polymorphisms in the prediction of pediatric infectious disease incidence and outcomes. The heterogeneity of available studies, given by the different age groups, ethnicity of populations enrolled and geographical locations greatly influences available results and their interpretation.