Thiamine (vitamin B1) 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 United States is most often seen in those who abuse alcohol (alcoholism). A lot of alcohol makes it hard for the body to absorb thiamine from foods. Unless those with alcoholism receive higher-than-normal amounts of thiamine to make up for the difference, the body will not get enough of the substance. This can lead to a disease called beriberi .

In severe thiamine deficiency, brain damage can occur. One type is called Korsakoff syndrome . The other is Wernicke's disease . Either or both of these conditions can occur in the same person.

There is no known poisoning linked to thiamine.

Recommended dietary allowances (RDAs) are the levels of essential nutrients that the Food and Nutrition Board at the Institute of Medicine believes meets the known nutrient needs of almost all healthy persons.

Specific recommendations for each vitamin depend on age, gender, and other factors (such as pregnancy). Adults and pregnant or lactating women need higher levels of thiamine than young children.

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 .