In the blood, the concentration is relatively low, while the plasma circulates predominantly free
thiamine, in erythrocytes and leukocytes - its phosphoric esters. Phosphorylation occurs in the liver. The most active phosphoric ester is thiamine diphosphate, which has coenzyme activity. It accumulates mainly in the liver, heart, brain, kidneys, spleen. 1/2 of the total amount is contained in striated muscles and myocardium and about 40% in internal organs. It is excreted through the intestines and kidneys.