 Thiamine vitamin B1 is a water-soluble vitamin. It is absorbed from the gastrointestinal tract and taken up into tissues by transport proteins and converted to thiamine pyrophosphate TPP by thiamine pyrophosphokinase TPPK. TPP is a co-factor of pyruvate dehydrogenase PDH, α-ketoglutarate dehydrogenase and transketolase TKTenzymes involved in the metabolism of glucose. 