Vitamin D Treat-to-Target Strategy for Children With Overactive Bladder-Wet

Inclusion Criteria: * Children older than or equal to 5 years of age with a diagnosis of wet OAB (the diagnosis followed the latest guidelines of ICCS) attending the outpatient clinic of the Department of Urology of the Affiliated Children's Hospital of Chongqing Medical University, * children with serum vitamin D levels below 35 ng/ml as indicated by the tests conducted by the hospital * children whose guardians have given their informed consent, are able to ensure compliance and have signed a paper-based informed consent form. Exclusion Criteria: * Those with urinary malformations or serious diseases (e.g., hypospadias, cryptorchidism, posterior urethral valvulae, vesicoureteral reflux, neurogenic bladder, urinary tumors, urinary stones, bladder and urethral injuries, etc.) * Those with neurological disorders (e.g., epilepsy, spinal cord injuries, spinal dysplasia, spinal embolism syndrome, multiple sclerosis, and autism spectrum disorders, etc.) * People with serious heart disease, abnormal liver and kidney function, lung disease, bone deformity, serious digestive tract disease, genetic metabolic disease * People with history of gastrointestinal surgery and urological surgery * People with dry stools and long-term constipation * People who are taking anticonvulsant and antiepileptic drugs, hormones, and anti-tuberculosis drugs * People with history of hypercalcemia, hyperphosphatemia with renal rickets * People who have had unexplained hematuria and hematuria with renal rickets within the last year * People who have been suffering from severe heart disease or chronic diabetes. * participation in other clinical studies at the time of consultation or during the follow-up period of other clinical studies * unwillingness to participate in this study