The thiamin molecule comprises substituted pyrimidine and thiazole moieties linked by a methylene bridge.
Vitamin B1 was given the name thiamin because it contains a thiol (sulfur) group and an amine (nitrogen) group.
Thiamin functions as a coenzyme in the metabolism of carbohydrates and branched chain amino acids. Although thiamin, per se, is not an energy-yielding nutrient, its coenzyme form TPP is needed for ATP production.
TPP or thiamin triphosphate functions as a coenzyme, catalyzing reactions that enable the body to use glucose, amino acids and fatty acids for energy.
Absorption of thiamin occurs mainly in the jejunum, at lower concentration as an active, carrier mediated system involving phosphorylation and at higher concentration by passive diffusion.
The classic pathological condition rusting from a gross deficiency of thiamin in humans is beriberi, which is prevalent in Far Eastern populations where unfortified polished rice is staple diet.
Thiamin in human body