<prompt> Test to diagnose thiamine deficiency ?RBC transketolaseFIGLU excretionMethyl-malunic acid in urineHistidine load test  <response>: Ans. is a i.e., RBC transketolase Thiamine diphosphate is also the coenzume for transketolase, in the pentose phosphate pathway.Therefore, thiamine nutritional status is best assessed by erythrocyte preferred or whole blood transketolase activity.. 