Vitamin B1 (Thiamin)

Jansen and Donath (1926) identified thiamin as the active factor in rice polishings and rice bran that prevents the disease beriberi in humans. In later studies, Kinnersly and Peters (1928) isolated thiamin from yeast and wheat germ. A synthetic process was developed for the production of this vitamin in 1936 (Robinson, 1966). Thiamin is a white hygroscopic crystalline compound that is stable at temperatures up to 100ºC and is readily soluble in water. Thiamin consists of a pyrimidine nucleus and a thiazole ring linked by a methylene bridge.
Thiamin synthesis occurs only in plants and microbes; therefore, virtually all animals have nutritional requirements for this vitamin. There are a number of factors that can affect an animal’s dietary requirement for the vitamin. Adult ruminants and horses can obtain adequate quantities of thiamin from bacteria in the rumen or cecum. However, young ruminants between the ages of 2 to 7 months can, under certain circumstances, develop polioencephalomalacia (cerebrocortical necrosis) in which thiamin deficiency plays an essential role. This disease appears to result from either the ruminal destruction of formed thiamin or from the presence of anti-thiamin compounds there.