Efficacy and Safety of Vitamin D in the Treatment of OAB-wet in Children

The purpose of this clinical trial is to investigate whether standard behavioral therapy combined with high-dose vitamin D (2400iu daily) is superior to standard behavioral therapy alone and standard behavioral therapy combined with solifenacin medication in improving frequency of incontinence and lower urinary tract symptom scores in children with wet OAB. Dedicated to understanding the current best treatment for wet OAB and to informing future clinical decisions and improving patient prognosis. The main questions it seeks to answer are

* Question 1 To attempt to elucidate the relationship between vitamin D levels and their lower urinary tract symptoms.
* Question 2 To examine the etiologic role of vitamin D in wet OAB in children.
* Question 3 Compare the effectiveness and safety of interventions to elucidate the etiologic mechanisms and optimal intervention strategies for wet OAB in children.

The researchers will compare (1) standard behavioral therapy with solifenacin (2) standard behavioral therapy with high-dose vitamin D (3) standard behavioral therapy alone to observe the clinical efficacy and safety of the three interventions for children with wet OAB.

\[Study Objective\]. Primary objective: to investigate whether standard behavioral therapy combined with high-dose vitamin D (2400iu per day) is superior to standard behavioral therapy alone and standard behavioral therapy combined with solifenacin medication in improving frequency of urinary incontinence and lower urinary tract symptom scores in children with wet OAB.

Secondary objectives:

1. To investigate whether this standard behavioral therapy combined with oral solifenacin and vitamin D supplementation regimen is superior to the remaining two groups in the following secondary efficacy outcomes.

   * Number of urinations per day
   * number of nocturia
   * Quality of life
   * Serum vitamin D levels
   * Overall patient satisfaction with treatment
2. To examine whether any effect of vitamin D supplementation on the above outcomes is modified by baseline vitamin D levels, and baseline lower urinary tract symptom severity (secondary outcome, efficacy).
3. Explore whether the treatment regimen of standard behavioral therapy combined with oral solifenacin and vitamin D is safe and well tolerated (secondary outcome, safety).

\[Study Steps\].

1. Design of Randomization Methods: After completion of a comprehensive baseline assessment, eligible participants are randomized 1:1:1 into three distinct intervention groups. Statisticians independent of this clinical monitoring will generate a randomization table from the PROC PLAN process of the SAS program based on predetermined seed and block numbers. The generated randomization codes will be recorded sequentially in sealed envelopes entrusted to the custody of the residents not involved in the trial.
2. Procedure for inclusion of study subjects: participants will be selected among patients with confirmed wet OAB and serum vitamin D levels below 35 ng/ml in the urology department of our hospital. We will exclude patients with other organic diseases and poor compliance. The guardians of the children will obtain informed consent and sign a paper consent form before starting the intervention.

4.Clinical data collection: information on the demographic characteristics of the child at the initial visit, medical history, family history, history of maternal vitamin D supplementation during pregnancy, history of vitamin D supplementation in the child, laboratory findings (serum vitamin D, routine urinalysis), abdominal imaging findings, and a diary of voiding will be kept by the participant for 7 days to establish a baseline.

Eligibility Criteria:
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