<prompt> Thiamine deficiency is best diagnosed by?Thiamine level in bloodTransketolase level in bloodAldolase level in bloodThiamine level in urine  <response>: THIAMINE VITAMIN B1Thiamine 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.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 citric acid cycle, which catalyzes the conversion of a-ketogluta rate to succinyl CoA.Branched-chain keto acid dehydrogenase which catalyzes the oxidative decarboxylation of branched chain keto amino acids, i.e. leucine, isoleucine and valine.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.Deficiency of thiamine causes :BeriberiWernickes encephalopathy, with korsakoff psychosisLactic acidosis 