V i t a m i n B 1
Vitamin B1 (Thiamine) is involved in numerous body functions, including nervous system and muscle functioning (flow of electrolytes in and out of nerve and muscle cells), multiple enzyme processes (via the coenzyme thiamine pyrophosphate), carbohydrate metabolism, maintaining normal heart function, proper formation of blood and the production of hydrochloric acid for the stomach.
Vitamin B1 helps the body to convert food (carbohydrates) into fuel (glucose), particulary vital in turning carbohydrates into energy for the brain. As well as metabolizing fats and proteins.
One of the main functions is producing energy for the body. Like all B vitamins, riboflavin is necessary in order for the body to convert carbohydrates from food into glucose. Additionally, riboflavin helps the body metabolize proteins and fats. Vitamin B1 is utilized as coenzyme, component of enzymes, which speed up biological and chemical reactions in the body.
Vitamin B1 is required for the processing of carbohydrates, fat, and protein, and using them to create energy in the form of ATP. Nerve cells also need vitamin B1 for normal functioning. Thiamin also promotes good circulation and supports normal cognitive brain function.
Vitamin B1 helps regulating the production of hydrochloric acid, which is integral for maintaining proper digestive function.
Vitamin B1 is more dependent on its fellow B vitamins than any other. Absorption of thiamin into the body requires adequate supplies of vitamin B6, vitamin B12 and folic acid. A deficiency in vitamin B12 can increase loss of thiamin in the urine, and vitamin B6 appears to help regulate distribution of thiamin throughout the body.
In general, cereal grains are the most important dietary sources of Vitamin B1. Of these, whole grains contain more Vitamin B1 than refined grains, as thiamine is found mostly in the outer layers of the grain and in the germ (which are removed in most refining processes).
Human storage of thiamine is about 25 to 30 mg, with the greatest concentrations in skeletal muscle, heart, brain, liver and kidneys. Because there is very little thiamine stored in the body, depletion can occur within 14 days.
Since Vitamin B1 is highly unstable, easily damaged by heat (cooking) and is also depleted by use of coffee, tannin from black teas, nicotine and alcohol, it is necessary to insure that intake of thiamine is optimal.
1.2 mg RDA - 100 mg UL
Loss through industrial processing:
Loss through cooking:
Loss through refrigeration:
RDA (recommanded dietary allowances) per day 
UL (tolerable upper intake level) per day 
 Dietary Reference Intakes: Vitamins.
The National Academies, 2001
 Risikofaktor: Vitamin Deficiency
Andreas Jopp, German Language, 2010