title: The relationship between plasma and red cell B-vitamin concentrations in critically-ill patients.
abstract: OBJECTIVE
  Low vitamin B-complex status has been associated with poorer outcome in critically-ill patients. However, these findings have been based on indirect methods. Using direct methods for assessing vitamin status, we examined the effect of B-complex vitamin supplementation by measuring plasma and red blood cell B1, B2 and B6-vitamin concentrations in critically-ill patients.
  
  
  METHODS
  Thiamine diphosphate (TDP), flavin adenine dinucleotide (FAD) and pyridoxal phosphate (PLP) concentrations were measured in plasma and red cells of normal subjects (n=49) and ITU patients (n=41).
  
  
  RESULTS
  Compared with the normal subjects, critically-ill patients had higher C-reactive protein and lower albumin concentrations (P<0.001). Also, plasma FAD and PLP were lower (P<0.001) and red cell concentrations of both were higher (P<0.01) in critically-ill patients. Critically-ill patients were grouped according to whether (n=23) or not (n=18) they had been supplemented with B-complex vitamins. Compared with non-supplemented group, the supplemented group had significantly higher red cell TDP and PLP concentrations (P<0.01). Plasma FAD and PLP concentrations did not differ significantly between the groups.
  
  
  CONCLUSIONS
  The results of the present study suggest that direct measurements of red cell FAD and PLP are more responsive to supplementation than plasma measurements in the critically-ill patient.
authors.affiliation: University Department of Surgery, Royal Infirmary, Glasgow G31 2ER, UK; University Department of Anaesthesia, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Tara
authors.initials: T
authors.lastname: Quasim
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
authors.forename: Aikaterina
authors.initials: A
authors.lastname: Vasilaki
authors.forename: Denis
authors.initials: D
authors.lastname: St J O'Reilly
authors.forename: John
authors.initials: J
authors.lastname: Kinsella
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D016638:Critical Illness; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005182:Flavin-Adenine Dinucleotide / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D011732:Pyridoxal Phosphate / Q000097:blood* / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism; D013835:Thiamine Pyrophosphate / Q000097:blood* / Q000378:metabolism; D014803:Vitamin B Complex / Q000097:blood* / Q000378:metabolism
chemical_list: D015415:Biomarkers; D012709:Serum Albumin; D014803:Vitamin B Complex; D005182:Flavin-Adenine Dinucleotide; D011732:Pyridoxal Phosphate; D002097:C-Reactive Protein; D013835:Thiamine Pyrophosphate