<prompt> Thiamine deficiency is best diagnosed the -Thiamine level in bloodThe transketolase level in the bloodAldolase level in the bloodThiamine level in urine  <response>: Ans. is b i.e., Transketolase level in blood THIAMINE VITAMIN B1o Thiamine is also called aneurine. Thiamine has a central role in energy-yielding metabolism and especially the metabolism of carbohydrates. The active form of thiamine is thiamine pyrophosphate TTP also called thiamine diphosphate TDP.o Thiamine diphosphate TDP or TPP is the coenzyme for three multienzyme complexes that catalyze oxidative decarboxylation :Pyruvate dehydrogenase in carbohydrate metabolism, which catalyzes the conversion of pyruvate to acetyl CoA.a-Ketoglutarate dehydrogenase in the citric acid cycle, which catalyzes the conversion of a-ketoglutarate to succinyl CoA.Branched-chain keto acid dehy drogenase which catalyzes the oxidative decarboxylation of branched chain keto amino acids, i.e. leucine, isoleucine and valine.o Thiamine diphosphate is also the coenzume for transketolase, in the pentose phosphate pathway. There- fore, thiamine nutritional status is best assessed by erythrocyte preferred or whole blood transketolase activity.o Deficiency of thiamine causes :BeriberiWernickes encephalopathy, with korsakoff psychosisLactic acidosis 