Vitamin B1 in human body

Vitamin B1 or 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.
Vitamin B1 in human body

Thiamine in Food

Thiamine is a generic term applied to all substances possessing vitamin B1 activity, regardless of the anion attached to the molecule. Thiamine the biologically active thiamine pyrophosphate (diphospho-thiamine, cocarboxylase) has an important role in carbohydrate metabolism as a co-enzymes.

This substance is heat and oxygen stable in its dry form, heat and alkali reactive in solution and stabilized by acid.

Thiamine supplementation is usually provided in vitamin B –complex formulations, in most multivitamin preparation and in vitamin enriched foods such as cereals. Breakfast cereals and bread are often supplemented with additional vitamin B1. Thiamine is found widely distributed in foods. Thiamine is found in all plants and is synthesized by some microorganism, particularly yeasts.

Thiamine does not appear to be stored in the body to any appreciable extent; consequently, deficiency symptoms may be observed within a few weeks in subjects maintained on a deficient diet. The disease known as beriberi, which has neurological and cardiac symptoms, results from a severe dietary deficiency of thiamine.

In the diagnosis of thiamine deficiency, symptoms to be noted in particular are anorexia, fatigue, loss of weight, sensation of burning in the soles of the feet, tenderness in calf muscles, muscle cramps and general muscular weakness.
Thiamine in Food