This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
Which of the vitamin deficiency lead to lacticacidosis? 
Select and explain. 
A. Riboflavin, B. Thiamin, C. Niacin, D. Panthotheic acid
B: Thiamin
Answer: B: Thiamin 
Explanation: Thiamin "The role of thiamin diphosphate in pyruvate dehydrogenase means that in deficiency there is impaired conversion of pyruvate to acetyl CoA. In subjects on a relatively high carbohydrate diet, this results in increased plasma concentrations of lactate and pyruvate, which may cause life-threatening lactic acidosis."- Harper Biologically active form of Thiamin (vitamin B1) is Thiamin pyrophosphate or Thiamin diphosphate. Thiamin diphosphate is the coenzyme for 3 multi-enzyme complexes that catalyze oxidative decarboxylation reactions: a. Pyruvate dehydrogenase complex which conves pyruvic acid to acetyl CoA b. Alpha-ketoglutarate dehydrogenase complex in the citric acid cycle which conves alpha-ketoglutarate to succinyl CoA c. Branched-chain keto-acid dehydrogenase involved in the metabolism of leucine, isoleucine, and valine. Thiamin diphosphate is also the coenzyme for transketolase in the HMP pathway of glucose metabolism.