Serum 25-Hydroxyvitamin D in Children with Newly Diagnosed Type 1 Diabetes: Associations with Diabetic Ketoacidosis and Acute Kidney Injury

Abstract Background . Vitamin D deficiency (VDD) is common among children and adolescents with type 1 diabetes mellitus (T1DM), particularly at the time of diagnosis. We investigated serum 25-hydroxyvitamin D [25(OH)D] concentrations according to the presence of DKA and AKI and assessed their associations with metabolic acidosis, renal function, and inflammatory markers. Methods . This retrospective study included 400 children with newly diagnosed T1DM (mean age 9.02 ± 4.18 years). Serum 25(OH)D was measured after resolution of DKA and severe hyperglycaemia. Patients were classified as non-DKA (n = 172), DKA without AKI (n = 208), or DKA with AKI (n = 20). AKI was defined according to KDIGO criteria. Results . The mean serum 25(OH)D concentration was 21.77 ± 8.87 ng/mL, and VDD was present in 44.5% of patients. VDD prevalence increased from 36.6% in non-DKA patients to 47.6% in DKA without AKI and 80.0% in DKA with AKI (p < 0.001). The DKA + AKI group had the lowest 25(OH)D concentration (16.52 ± 9.39 ng/mL). Serum 25(OH)D and eGFR were positively correlated with blood pH and bicarbonate and negatively correlated with leukocyte, neutrophil, and monocyte counts. eGFR was inversely correlated with corrected serum sodium. No significant association was observed between 25(OH)D and eGFR. Conclusions . VDD is common at T1DM onset and is particularly prevalent in children with DKA complicated by AKI. Lower 25(OH)D concentrations were associated with greater preceding acidosis and inflammatory activation. AKI during DKA appears to have a multifactorial pathophysiology involving volume depletion and systemic inflammation. The association between VDD and AKI is clinically relevant but needs further investigation.