Effect of vitamin D on Helicobacter pylori infection and eradication: An updated systematic review and meta‐analysis

Background: Various studies that have examined the association between Helicobacter pylori (H pylori) and vitamin D (۲۵-hydroxyvitamin D [۲۵(OH)D]) have reported different and sometimes controversial results.Objectives: Therefore, this systematic review and meta-analysis was performed to investigate the relationship between vitamin D and H pylori infection and its eradication.Methods: Observational studies published in English were searched in PubMed, Scopus, and ISI databases until ۱ August ۲۰۲۱. The standardized mean difference (SMD) was used to evaluate the probability ratio of H pylori infection and its eradication in the group with low vitamin D levels and the control group. Pooled estimation was calculated by random effects model. Heterogeneity was assessed by Cochran's Q test and I۲ index.Results: Twelve studies were analyzed in this meta-analysis, and the results showed that the level of ۲۵(OH)D in H pylori‐positive patients was significantly lower than those without infection (SMD= -۰.۶۶ ng/mL, ۹۵% CI: -۰.۹۹, -۰.۳۳, P<۰.۰۰۱). Also, the level of ۲۵(OH)D in H pylori successful eradication individuals was significantly higher than those with unsuccessful eradication (SMD=۱.۵۳ ng/mL, ۹۵%CI: ۱.۳۴-۱.۷۱, P<۰.۰۰۱).Conclusion: There is a significant relationship between vitamin D levels and H pylori infection and its eradication. Therefore, it is necessary to pay attention to the vitamin D level in treating H pylori infection.