title: Vitamin A, E, B12, and folic acid in end-stage renal disease Tunisian patients: status and predictive value for overall mortality and cardiovascular events.
abstract: BACKGROUND
  Vitamin status and role in end stage renal disease (ESRD) is controversial. This study was aimed at assessing vitamin A, E, B12, and folic acid status in Tunisian ESRD patients and testing their predictive value for overall mortality and cardiovascular events (CVE).
  
  
  METHODS
  We examined plasma vitamin A, E, B12, and folic acid in 115 ESRD patients and looked for any correlation with all-cause mortality and CVE after a six year follow-up. Vitamin A and E were determined by HPLC and vitamin B12 and folic acid were determined by enzyme immunoassay.
  
  
  RESULTS
  At enrolment, plasma vitamin A was higher in patients than controls, while plasma vitamin B12 was higher in HD patients. No significant differences were observed for plasma vitamin E and folic acid concentrations between patients and controls. Folic acid and vitamin B12 levels were higher in supplemented patients. During the follow-up period, 17 patients were lost, 15 died, and 36 presented a CVE. Survival analysis showed that mortality and/or CVE trend to be lower for high folic acid levels (Log Rank = 0.098). Cox's regression analysis showed that high levels of folic acid are inversely related to all-cause mortality and/or CVE [Hazard ratio (95% confidence interval), 0.255 (0.08 - 0.740); p = 0.012].
  
  
  CONCLUSIONS
  Plasma vitamins A, E, B12, and folic acid concentrations are usually normal in Tunisian ESRD patients. High folic acid levels are associated with fewer CVE and better survival. However, as uremia could be associated with functional vitamin deficiency, maintaining high plasma vitamin levels by adequate nutrition and tolerable supplementation would be beneficial in ESRD patients.
authors.affiliation: LR99ES11 and UR05/0808, Biochemistry Laboratory, Rabta Hospital, Faculty of Medicine of Tunis, El Manar University, Tunis, Tunisia.
authors.forename: Hayet
authors.initials: H
authors.lastname: Fellah
authors.forename: Moncef
authors.initials: M
authors.lastname: Feki
authors.forename: Sameh Hadj
authors.initials: SH
authors.lastname: Taieb
authors.forename: Bassem
authors.initials: B
authors.lastname: Hammami
authors.forename: Karima
authors.initials: K
authors.lastname: Boubaker
authors.forename: Bernard
authors.initials: B
authors.lastname: Lacour
authors.forename: Taieb
authors.initials: T
authors.lastname: Ben Abdallah
authors.forename: Naziha
authors.initials: N
authors.lastname: Kaabachi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology; D002423:Cause of Death; D015897:Comorbidity; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012907:Smoking / Q000097:blood / Q000453:epidemiology; D014416:Tunisia / Q000453:epidemiology; D014801:Vitamin A / Q000097:blood*; D014805:Vitamin B 12 / Q000097:blood; D014810:Vitamin E / Q000097:blood*; D055815:Young Adult
chemical_list: D014801:Vitamin A; D014810:Vitamin E; D005492:Folic Acid; D014805:Vitamin B 12