Effects of Thiamin Deficiency on Carbohydrate Metabolism

The role of thiamin diphosphate in pymvate dehydrogenase means that, in deficiency, there is impaired conversion of pymvate to acetyl GoA, and hence impaired entry of pymvate into the citric acid cycle. Especially in subjects on a relatively high carbohydrate diet, this results in increased plasma concentrations oflactate and pymvate, which may lead to life-threateninglactic acidosis. 

The increase in plasma lactate and pyruvate after a test dose of glucose was used historically as a means of assessing thiamin nutritional status (Section 6.5). 

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