title: Oral vitamin C administration increases lipid peroxidation in hemodialysis patients.
abstract: BACKGROUND
  Since vitamin C (ascorbic acid, AA) deficiency is common in hemodialysis patients, systematic supplementation has been recommended. Further, vitamin C has been advocated as a potential adjuvant to erythropoietin by virtue of its capacity to improve iron utilization. However, vitamin C may have a paradoxical pro-oxidant effect in the presence of iron.
  
  
  METHODS
  In 109 hemodialysis patients, oral vitamin C was administered at 360 and 1,500 mg/week during 3 months each, followed by a wash-out period of 3 months.
  
  
  RESULTS
  Serum AA increased from 0.22 to 0.33 and 0.63 mg/dl after 360 and 1,500 mg/week, respectively. However, a commensurate increase of plasma malondialdehyde (MDA), a parameter of lipid peroxidation, with 9 and 26% was observed. Serum AA and plasma MDA returned to baseline after withdrawal of vitamin C. Parameters of iron status, nutrition, inflammation, dialysis efficiency and plasma lipids remained unaltered. In a stepwise multiple regression analysis, serum AA and ferritin were strong and independent predictors of MDA.
  
  
  CONCLUSIONS
  Oral vitamin C supplementation in hemodialysis patients increases lipid peroxidation, especially in patients with increased serum ferritin. The potential benefits of restored vitamin C status and improved erythropoiesis may be entirely overruled by the adverse consequences of oxidative tissue injury.
authors: Renal Unit, AZ Sint-Jan AV, Brugge, Belgium. an.devriese@azbrugge.be
authors: An S
authors: AS
authors: De Vriese
authors: Daniëlle
authors: D
authors: Borrey
authors: Els
authors: E
authors: Mahieu
authors: Ilse
authors: I
authors: Claeys
authors: Lut
authors: L
authors: Stevens
authors: Ann
authors: A
authors: Vanhaeverbeke
authors: Mieke
authors: M
authors: Roelens
authors: Michel R
authors: MR
authors: Langlois
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D006435:Renal Dialysis / Q000379:methods / Q000639:trends*
chemical_list: D001205:Ascorbic Acid