RESUMO
BACKGROUND AND AIMS: 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.
