Loss via peritoneal fluid as a factor for low 25(OH)D3 level in peritoneal dialysis patients.

Background/aims: In patients with end-stage renal disease (ESRD), the 25-hydroxyvitamin D3 (25(OH)D3) level is known to be lower compared to that of the normal population. In the present study, we evaluated the influences of dialysis methods on the serum 25(OH)D3 level in patients with ESRD who are treated with hemodialysis and peritoneal dialysis.

Methods: Thirty-nine peritoneal dialysis (PD), 49 hemodialysis (HD) patients, and 33 healthy controls were included in the present study. The mean HD period was 30.38 +/- 21.81 months and the mean PD period was 26.35 +/- 24.04 months. Serum samples from the HD and PD patients and healthy controls were examined in terms of 25(OH)D3, intact parathyroid hormone (iPTH), and other biochemical laboratory tests. Additionally, the 25(OH)D3 level in the peritoneal fluid was analyzed in the PD group.

Results: The mean 25(OH)D3 levels in the control, HD, and PD groups were 26.63 +/- 10.89, 21.65 +/- 12.38, and 13.46 +/- 9.41 nmol/l, respectively (P < 0.001). The mean peritoneal fluid 25(OH)D3 level was 28.53 +/- 7.66 nmol/l. Moreover, blood and PD fluid 25(OH)D3 levels were 34 compared in the PD group. The 25(OH)D3 level in dialysate was higher than that of serum in PD patients (P < 0.001).

Conclusion: The significantly lower blood levels of 25(OH)D3 in PD patients compared to those of HD patients were thought to be due to 25(OH)D3 loss via peritoneal fluid.