This randomized clinical trial evaluated three treatment approaches for children aged 6 to 12 years who had primary monosymptomatic nocturnal enuresis (night-time bedwetting) and confirmed vitamin D deficiency. Bedwetting is common in school-aged children and can affect self-esteem, social interactions, and school performance. Although desmopressin is widely used, some children do not respond adequately. Previous studies suggested that low vitamin D levels might contribute to bedwetting, raising the possibility that vitamin D supplementation could help.

In this study, eligible children were randomly assigned to one of three groups:

1. vitamin D supplementation alone,
2. desmopressin alone, or
3. a combination of vitamin D and desmopressin.

All participants were followed for up to six months. The primary aim was to compare the improvement in the number of wet nights per week among the three groups. Secondary assessments included treatment tolerability, changes in vitamin D levels, changes in serum sodium, and any treatment-related side effects.

Inclusion Criteria:

• Children and adolescents aged 6 to 12 years
• Primary monosymptomatic nocturnal enuresis
• At least 2 episodes of night-time bedwetting per week for ≥3 consecutive months
• Serum 25-hydroxyvitamin D level <20 ng/mL
• Normal kidney function
• Normal serum sodium level
• Absence of daytime lower urinary tract symptoms (urgency, frequency, dysuria)
• Informed consent from parent or guardian and assent from the child when appropriate

Exclusion Criteria:

• Non-monosymptomatic nocturnal enuresis (daytime storage or voiding symptoms)
• Congenital urinary tract anomalies (e.g., meatal stenosis, hypospadias, epispadias)
• Urinary tract infection until culture becomes negative
• Neurological abnormalities, including suspected neurogenic bladder
• Endocrine diseases such as diabetes mellitus or hyperthyroidism
• Congestive heart failure or significant cardiac disease
• Prior or current use of vitamin D supplementation
• Serum sodium below normal range
• Chronic systemic illness
• Any condition judged by investigators to interfere with study participation

De-identified individual participant data (IPD) underlying the study results may be shared with qualified researchers upon reasonable request. Shared data will include variables necessary to confirm the primary and secondary outcome analyses. No information that could identify participants will be provided.

Data will be available beginning 6 months after publication of the study results and will remain available for 3 years thereafter.

Researchers must submit a methodologically sound proposal outlining the intended use of the data. Access will be granted after review and approval by the study's principal investigator and the ethics committee. A data use agreement will be required before data are released.