Vitamin B1—Thiamin, the Carbo Burner

Vitamin B1—Thiamin, the Carbo Burner

 Thiamin was first discovered in Japan in the early 1900s, when the lack of thiamin in white rice caused beriberi. Thiamin was first synthesized in 1936. Thiamin is found in rice bran and rice germ, both of which are removed when white rice is made from brown rice.

Thiamin plays a key role in the metabolism of energy in all cells. Thiamin is part of the coenzyme ThiaminPyroPhosphate (TPP), which helps convert pyruvate to acetyl-coenzyme A (also known as acetyl-CoA). This is a necessary step in the production of cellular energy from carbohydrates. Magnesium is needed to convert thiamin to TPP. Although refined grains are often fortified with thiamin, their original magnesium is depleted by an average of 76 percent. Magnesium deficiency may also have played a part in beriberi since so much magnesium is lost when white rice is refined.

Thiamin is also found in the form of thiamin triphosphate in nerve and muscle cells. This form of thiamin activates the transport of electrolytes across the membranes of nerve and muscle cells. This allows healthy nerve conduction and muscle action. The amount of dietary thiamin needed is based on the amount needed in producing energy. Thiamin needs will be met by most normal diets if enough food is eaten to meet energy requirements. People generally get enough thiamin to meet the Recommended Daily Allowance (RDA), although marginal thiamin deficiency affects about one quarter of the people in the United States and Canada. Elderly people are at risk of thiamin deficiency because of low intakes and reduced absorption.

Cooking can reduce thiamin in two ways. Thiamin is destroyed by heat. Also,thiamin is easily leached out of food by water. To minimize the loss of thiamin and other water-soluble vitamins during cooking, food can be steamed or made into stews and soups.