Abstract: Objective To study the correlation between 25-hydroxy vitamin D₃ and the status of iron metabolism in patients with continuous ambulatory peritoneal dialysis (CAPD). Methods A total of 50 patients treated with CAPD for more than one year with a stable disease condition in the Peritoneal Dialysis Clinic of this hospital were enrolled in this study (CAPD group). A total of 30 healthy subjects from the Health Checkup Center were selected as the control group. Serum 25-hydroxy vitamin D₃ and hepcidin were measured by enzyme- linked immunosorbent assay (ELISA). Hemoglobin (HB), blood biochemistry, serum iron, ferritin (Fer) and total iron binding capacity (TIBC) were assay by routine laboratory methods. Pearson correlation analysis was used to analyze the correlation between serum 25-hydroxy vitamin D₃ and clinic indices. Results As compared with control group, CAPD group had significantly lower serum 25-hydroxy vitamin D₃ (t=1.947, P=0.029), HB (t=6.676, P＜0.001), iron (t=8.463, P＜0.001) and TIBC (t=6.173, P＜0.001), significantly higher serum Fer (t=3.084, P= 0.003), higher hepcidin but without statistical significance (t=1.280, P=0.204), and significantly higher serum creatinine (t=22.810, P＜0.001), blood urea nitrogen (t=16.580, P＜0.001), phosphorus (t=3.372, P＜0.001) and parathyroid hormone (t=8.010, P＜0.001). Pearson correlation analysis revealed that serum 25- hydroxy vitamin D₃ was negative correlated with hepcidin (r=- 0.382, P=0.003). Conclusion The lower level of serum 25-hydroxy vitamin D₃ is associated with the abnormal iron metabolism and anemia in CAPD patients.

Key words: peritoneal dialysis, vitaminD₃, iron metabolism