Thiamine is one of the B vitamins, a group of water-soluble vitamins that participate in many of the chemical reactions in the body.

Thiamine (vitamin B-1) helps the body cells convert carbohydrates into energy. It is also essential for the functioning of the heart, muscles, and nervous system.

Thiamine is found in fortified breads, cereals, pasta, whole grains (especially wheat germ), lean meats (especially pork), fish, dried beans, peas, and soybeans.

Dairy products, fruits, and vegetables are not very high in thiamine, but when consumed in large amounts, they become a significant source.

A deficiency of thiamine can cause weakness, fatigue, psychosis, and nerve damage. Thiamine deficiency in the U.S. is most often seen in alcoholics, because heavy drinking limits the ability of the body to absorb this vitamin from foods. Since few alcoholics consume higher than normal amounts of thiamine to make up for the difference, they become deficient and may develop the disease called beriberi.

In severe deficiency, brain damage can occur. One type is called Korsakoff syndrome (confusion and loss of short-term memory); the other is Wernicke's disease (eye disturbances, unsteady gait, and confusion). Either or both of these conditions can occur in the same person.

There is no known toxicity associated with thiamine.

Recommended dietary allowances (RDAs) are the levels of essential nutrients that the Food and Nutrition Board has judged meet the known nutrient needs of almost all healthy persons.

Specific recommendations for each vitamin depend on age, gender, and other factors (such as pregnancy). The U.S. Department of Agriculture offers a PDF file that lists these recommendations.

The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid.