title: Concentrations of vitamin C, vitamin B12 and folic acid in patients treated with hemodialysis and on-line hemodiafiltration or hemofiltration.
abstract: OBJECTIVE
  Uncertainty has arisen as to whether vitamin supplements are needed by dialysis patients, in particular those treated by means of hemofiltration or hemodiafiltration using highly permeable (high-flux) filters. We therefore measured the concentrations of vitamin C, cobalamin (vitamin B12) and folic acid in conventional (low-flux) dialysis patients and in those receiving on-line treatment (hemofiltration or hemodiafiltration).
  
  
  METHODS
  Plasma (P-)ascorbate, serum (S-)cobalamin and S-folate concentrations were measured before and after a treatment session in 15 patients treated with low-flux hemodialysis and in 14 treated with on-line hemofiltration or hemodiafiltration. The patients' vitamin supplementations were also recorded.
  
  
  RESULTS
  P-ascorbate concentrations were lowered by 51% and 53% in the hemodialysis and on-line groups, respectively after treatment and this reduction was significant (p<0.001). Concentrations below the reference values were found in 12/14 patients not receiving vitamin C supplementation. S-cobalamin did not decrease in the hemodialysis or on-line groups. S-folates did not change significantly in the hemodialysis or filtration groups. Patients without folacin supplementation had low values.
  
  
  CONCLUSIONS
  P-ascorbate was reduced by both dialysis and filtration treatments. Neither S-cobalamin nor S-folate were reduced by dialysis or filtration treatments.
authors.affiliation: Dialysis Unit, Sophiahemmet, Queen Sophia Hospital, Stockholm, Sweden. ingela.fehrman@sophiahemmet.se
authors.forename: Ingela
authors.initials: I
authors.lastname: Fehrman-Ekholm
authors.forename: Agneta
authors.initials: A
authors.lastname: Lotsander
authors.forename: Katarina
authors.initials: K
authors.lastname: Logan
authors.forename: David
authors.initials: D
authors.lastname: Dunge
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Odar-Cederlöf
authors.forename: Anders
authors.initials: A
authors.lastname: Kallner
mesh_terms: D000368:Aged; D001205:Ascorbic Acid / Q000097:blood*; D015331:Cohort Studies; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006440:Hemofiltration; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000097:blood* / Q000150:complications / Q000628:therapy; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D005492:Folic Acid; D014805:Vitamin B 12; D001205:Ascorbic Acid