en Nephrology Nephrology Original Article Original Article <p style="text-align:justify"><span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:150%"><b><span style="line-height:150%"><span style="color:#0033ff;"><em>Background:</em></span> </span></b><span style="line-height:150%">Urinary tract infections (UTIs) are among the most prevalent infectious conditions, particularly in children. Vitamin D deficiency has been implicated in various infections, including UTIs. This study aimed to evaluate the association between serum vitamin D levels and UTIs in children at Amir Kola Children&#39;s Hospital.<b> </b></span></span><br> <span style="line-height:150%"><b><span style="line-height:150%"><span style="color:#0033ff;"><em>Methods:</em></span> </span></b><span style="line-height:150%">This case-control study was conducted on 120 children, aged 2&ndash;18 years, diagnosed with UTIs and referred to Amir Kola Children&#39;s Hospital, Babol, Iran. Participants were divided into two groups: 60 UTI cases and 60 healthy controls. Peripheral blood samples were collected for vitamin D analysis, measured via ELISA assay. Statistical analysis was performed using SPSS Version 26.<b> </b></span></span><br> <span style="line-height:150%"><b><span style="line-height:150%"><em><span style="color:#0033ff;">Results:</span></em> </span></b><span style="line-height:150%">The mean serum vitamin D level was 17.70 &plusmn; 8.35 ng/mL in the case group and 37.91 &plusmn; 12.18 ng/mL in the control group, revealing a significant reduction in vitamin D levels among UTI patients (p<0.001). Additionally, pyelonephritis was associated with severe vitamin D deficiency (P=0.02). Female children aged 3&ndash;5 years exhibited a higher risk of vitamin D deficiency, although age and sex did not significantly influence vitamin D levels overall. Vitamin D status was not correlated with hospitalization duration.</span></span><br> <span style="line-height:150%"><b><span style="line-height:150%"><em><span style="color:#0033ff;">Conclusion:</span></em> </span></b><span style="line-height:150%">Given its immunoprotective role, vitamin D screening and supplementation may serve as a preventive strategy against UTIs and contribute to improved clinical outcomes in affected children.</span></span></span></span><br> &nbsp;</p> vitamin D, UTI, urinary tract infections, cathelicidin 651 658 http://caspjim.com/browse.php?a_code=A-10-2467-1&slc_lang=en&sid=1 Masoumeh Piyadah Kouhsar Kouhsar@yahoo.com 100319475328460054744 100319475328460054744 No Student Research Committee, Babol University of Medical Sciences, Babol, Iran. Morteza alijanpour m.alijanpour@yahoo.com 100319475328460054745 100319475328460054745 No Non-Communicable Pediatric Diseases Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IR Iran. Mohammad Pornasrollah pornasrollah@yahoo.com 100319475328460054746 100319475328460054746 No Clinical Research Development Unit of Amirkola Children's Hospital, Babol University of Medical Sciences, Babol, IR Iran Hemat Gholinia h_gholinia@yahoo.com 100319475328460054747 100319475328460054747 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R.Iran. Sahar Sadr Moharerpour drsaharsadr@gmail.com 100319475328460054748 100319475328460054748 Yes Non-Communicable Pediatric Diseases Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, IR Iran