VITAMIN B1

also called Thiamine, or Thiamin, a water-soluble organic compound that is necessary in the diet of all animals except ruminants (e.g., cows) to prevent beriberi (q.v.), a disease characterized by multiple neuritis (lesions of nerves), general debility, and painful rigidity. Thiamine was the first vitamin to be isolated in pure form (1926). Its structure was fully elucidated and the vitamin synthesized in 1936. Thiamine plays an important role in carbohydrate metabolism. It carries out these functions in its active form, as a component of the coenzyme thiamine pyrophosphate. Thiamine is found most abundantly in cereal grains and in certain other seeds. Pork is one of the richest animal sources. The recommended daily intake of thiamine is 1.0 to 1.1 mg for adult women and 1.2 to 1.4 mg for adult men.