Evaluation of methods of coenzyme activation of erythrocyte enzymes for detection of deficiency of vitamins B1, B2, and B6

The authors describe optimized, ultraviolet spectrophotometric procedures for determination of erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase activity, and their activation by their respective coenzymes, thiamine pyrophosphate, flavin adenine dinucleotide, and pyridoxal 5 phosphate, as tests for vitamin B1, B2 and B6 deficiency. With these procedures the authors investigated healthy subjects on normal and vitamin supplemented diets, and a series of (mainly) alcoholic hospital inpatients. The enzyme procedures described have good precision and can be readily carried out in the routine laboratory. Abnormal transketolase activation correlated well with clinical evidence of vitamin B1 deficiency.