title: Vitamin D and vitamin-D-binding protein kinetics in patients treated with continuous ambulatory peritoneal dialysis (CAPD).
abstract: Serum and dialysate levels of 25-hydroxycholecalciferol (25-OHD3), 1,25 dihydroxycholecalciferol (1,25-(OH)2D3), and vitamin-D-binding protein (DBP) were measured in 14 patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Serum levels of 25-OHD3 and DBP were within normal range (29.1 +/- 22.9 nmol/L and 5.9 +/- 1.1 mumol/L, respectively). Serum levels of 1,25-(OH)2D3 were subnormal in all (less than 16 pmol/L) but one. In 5 patients, dialysate concentrations of 25-OHD3 were 2.3 +/- 0.9 nmol/L, the rest had levels less than 1.0 nmol/L. Small quantities of 1,25-(OH)2D3 were found in the dialysate effluents. DBP could be detected in the dialysate in all patients (0.24 +/- 0.06 mumol/L). Mass transfer (MT) of 25-OHD3 and DBP were respectively -10.4 +/- 8.3 nmol/24 h and -1.46 +/- 0.46 0.46 mumol/24 h. Peritoneal clearances of 25-OHD3 and DBP were low (0.40 +/- 0.37 mL/min and 0.18 +/- 0.06 mL/min, respectively. We conclude that CAPD leads to losses of 25-OHD3 and DBP. However, the peritoneal loss of DBP is well compensated and does not result in serum deficiency. Serum 25-OHD3 levels did not correlate with time on CAPD.
authors.affiliation: Department of Nephrology, Hvidovre Hospital, University of Copenhagen, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Joffe
authors.forename: J G
authors.initials: JG
authors.lastname: Heaf
mesh_terms: D002112:Calcifediol / Q000378:metabolism*; D002117:Calcitriol / Q000378:metabolism*; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000209:etiology; D015314:Dialysis Solutions / Q000032:analysis; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D013997:Time Factors; D014809:Vitamin D-Binding Protein / Q000378:metabolism*
chemical_list: D015314:Dialysis Solutions; D014809:Vitamin D-Binding Protein; D002117:Calcitriol; D002112:Calcifediol