Vitamin D and Urinary Tract Infection: A Systematic Review and Meta-Analysis.

Whether or not Vitamin D deficiency is associated with urinary tract infections (UTI) remains controversial. We retrieved relevant articles from the PubMed, Google Scholar, the Cochrane Library, Med-line and Embase databases up to Mach 1, 2018 for studies investigating the association between Vitamin D and UTI. The meta-analysis of 9 studies included 1921 participants, of which 580 were diagnosed with UTI. They showed that Vitamin D insufficiency was associated with a significantly increased risk of having a UTI (pooled OR=3.01, 95%CI=2.31-3.91), with moderate heterogeneity (I2 =49.5%). Moreover, Vitamin D level was significantly lower in the UTI group (standardized mean difference (SMD)=-1.65, 95%CI=-2.69--0.60, P<0.001). Significant heterogeneity was also detected (I2 =97.9%, P<0.001). Meta-analysis also revealed a significant association between UTI and Vitamin D deficiency in children (OR=4.78, 95%CI=3.08-7.44, P<0.001). This meta-analysis indicated a significant association between Vitamin D insufficiency and increased risk of UTI, especially in children.