The aim of this study is to give children with dry OAB: (1) Standard behavioral therapy combined with classical anticholinergic drugs (Solinaxine), or (2) standard behavioral therapy combined with short-term high-dose exogenous vitamin D supplementation are used to compare the outcomes of lower urinary tract symptoms in children with dry OAB during follow-up. To provide more robust supporting evidence for the broader promotion of short-term high-dose exogenous vitamin D supplements in combination with standard behavioral therapy as an effective treatment for dry OAB treatment in children.

Inclusion Criteria:

1. Children older than 5 years who were admitted to the Department of Urology, Children's Hospital Affiliated to Chongqing Medical University and diagnosed with dry OAB.
2. The results of our laboratory indicated that the serum vitamin D level was lower than 35ng/mL.
3. The child (guardian) has been informed of the nature of the study, understands the provisions in the protocol, is able to guarantee compliance, and signs the informed consent.

Exclusion Criteria:

1. Patients with other urinary system malformations or serious diseases (such as hypospadias, cryptorchidism, posterior urethral valvular disease, vesicoureteral reflux, neurogenic bladder, urinary system tumors, urinary calculi, bladder and urethral injuries, etc.);
2. complicated with neurological diseases (such as epilepsy, spinal cord injury, spinal cord dysplasia, tethered cord syndrome, multiple sclerosis, autism spectrum disorder, etc.);
3. Patients with severe heart disease, abnormal liver and kidney function, lung disease, bone malformation, severe digestive tract disease, and genetic metabolic disease;
4. History of gastrointestinal surgery and urinary system surgery;
5. Dry stool, long-term constipation;
6. are taking anticonvulsant and antiepileptic drugs, hormones, antituberculosis drugs;
7. Previous history of hypercalcemia, hyperphosphatemia with renal rickets;
8. History of unexplained hematuria and urinary tract infection in the past 1 year;
9. Have a history of allergy or allergic reaction to vitamin D preparations;
10. Participating in another clinical study at the time of visit or during the follow-up of another clinical study;
11. Those who did not want to participate in the study or had poor follow-up compliance