Losses of 1,25- and 24,25-Dihydroxycholecalciferol in the Peritoneal Fluid of Patients Treated with Continuous Ambulatory Peritoneal Dialysis

Abstract

We measured peritoneal losses of the active vitamin D metabolites 1,25(OH)₂D₃ and 24,25(OH)₂D₃ in patients receiving continuous ambulatory peritoneal dialysis (CAPD). The serum concentration of 24,25(OH)₂D₃ was considerably lower than in hemodialysis patients. The serum concentration of 1,25(OH)₂D₃ was undetectable and rose to levels similar to those in hemodialysis patients only after loading with much higher oral doses of 1-α-vitamin D₃ than those received by hemodialysis patients. Losses of both metabolites in peritoneal fluid were considerable, averaging approximately 6–8% of the plasma pool per day. These losses lead to low serum levels of these active vitamin D metabolites in CAPD patients, which may be an important factor in exacerbating renal osteodystrophy. Our results indicate the need for increased replacement doses of vitamin D metabolites in CAPD patients.

Prevalence of 25(OH) Vitamin D Insufficiency and Deficiency in Pediatric Patients on Chronic Dialysis

“…Previous reports suggested that PD patients are at especially high risk and might need supplementation with ergocalciferol because of ongoing loss of vitamin D binding protein through peritoneal effluent (20,21,(29)(30)(31)(32). Our results are compatible with those in previous reports and might favor supplementation with ergocalciferol in addition to active vitamin D sterols in pediatric patients on chronic dialysis.…”

“…Possible explanations for that finding include uremia, darker skin, and reduced sun exposure because of infirmity or dialysis modality. It is also known that suboptimal vitamin D status may be associated with the rate of progression of renal insufficiency (1)(2)(3)(4) (29)(30)(31)(32). Inadequate nutrition and low levels of vitamin D binding protein can play a role as contributing factors in CKD patients with low levels of serum albumin and vitamin D (16,19,32).…”

Enhancement of Ionized Calcium and 1,25-Dihydroxycholecalciferol Loss from Peritoneal Fluid during Peritonitis in Patients Treated with Continuous Ambulatory Peritoneal Dialysis

“…Recovery of vitamin D metabolites from the extraction and chromatography processes was estimated by the addition of known amounts of labelled metabolites to the original serum samples [12]. The recovery range for l,25(OH): D3 was 70.8±8.2%.…”

1,25-Dihydroxycholecalciferol and Peritoneal Macrophage Chemotaxis in Patients on Continuous Ambulatory Peritoneal Dialysis

“…In addition, patients on continu ous ambulatory peritoneal dialysis (CAPD) chronically lose vitamin D binding protein and 25-OH vitamin D into the peritoneal dialysate effluent [1,2]. Studies have docu mented a low serum 1,25-dihydroxycholecalciferol in most patients on CAPD [3,4], The uremic state itself is associated with defective delayed hypersensitivity and polymorphonuclear leukocyte chemotaxis [5,6], Despite dialysis, alterations in polymorph and monocyte func tions could persist [7,8].…”