Association Between Serum Vitamin D Levels and Mortality in Children Receiving Chronic Dialysis: A Retrospective Cohort Study.

Background: Vitamin D deficiency is highly prevalent among children on regular dialysis, affecting approximately 90% of patients. This deficiency (serum 25-hydroxyvitamin D < 50 nmol/L or 20 ng/mL) is associated with various complications, including skeletal problems, increased infection risk, arterial stiffness, vascular calcification, and higher cardiovascular mortality. Severe deficiency (< 30 nmol/L) particularly increases mortality risks. Method: In this cross-sectional retrospective study, we examined 53 pediatric patients (28 boys, 25 girls) undergoing regular dialysis (hemodialysis and peritoneal dialysis) at a children's medical center from 2018 to 2020. The mean age was 8.21 years, with 71.7% aged 2-12 years, 20.8% adolescents, and 7.5% under 2 years. The mean vitamin D level was 23.51 ng/mL. Results: Results showed that 26.41% of patients died, with mortality analysis revealing a hazard ratio of 3.2 for patients with vitamin D levels below 15 ng/mL. The mortality rate was 64.7% in severe deficiency (< 15 ng/mL), 18.8% in moderate deficiency (15-30 ng/mL), while patients with sufficient levels (> 30 ng/mL) recorded no deaths. Additionally, 11.32% developed skeletal disorders, including two cases of spinal fracture. Vitamin D levels showed significant positive correlations with calcium ( Conclusion: In conclusion, children with end-stage renal disease undergoing dialysis face increased risks of vitamin D deficiency due to impaired kidney function. This deficiency significantly impacts survival rates and contributes to poor outcomes. Regular monitoring and management of vitamin D levels are crucial for improving survival in pediatric dialysis patients.