Vitamin A supplementation is effective for improving the clinical symptoms of urinary tract infections and reducing renal scarring in girls with acute pyelonephritis: a randomized, double-blind placebo-controlled, clinical trial study

•Vitamin A supplementation is effective on reducing renal scarring secondary to APN on fever, urinary frequency and poor feeding duration in girls with APN.•Vitamin A supplementation is effective for improving the clinical symptoms of UTI.•Vitamin A supplementation could be reducing renal injury and scarring following APN in girls with first APN. It is believed that tubulointerstitial inflammation plays a role in the formation of renal scarring secondary to acute pyelonephritis (APN). Vitamin A is an anti-inflammatory agent that is involved in the re-epithelialization of damaged mucosal surfaces. The aim of this study was to evaluate the efficacy of vitamin A supplementation in combination with antibiotics for improving urinary tract infections (UTIs) symptoms and preventing renal scarring in girls with APN. This randomized, double-blind, placebo-controlled clinical trial was conducted on 90 girls aged 2 to 12 years old between 2015 and 2017. Patients with UTIs and first episode of APN diagnosed based on 99 mTc-DMSA scintigraphy (uptake defect) were assessed for eligibility. Patients were randomly divided into two groups that either received 10 days of oral vitamin A (intervention group) or 10 days of placebo (control group) in addition to antibiotics during the acute phase of infection. The clinical response was considered as the primary outcome [duration (positive days) of UTI symptoms during trial treatment period] and secondary outcomes (no change, improving and or worsening of 99 mTc-DMSA scan results 6 months after treatment from baseline). P