Vitamin B1 (Thiamine)

Vitamin B1 (thiamine) helps your body break down and use carbohydrates and certain amino acids for energy. Not getting enough thiamine is most often linked to heavy alcohol use or chronic illness. Early signs of low thiamine can include poor appetite, irritability, low mood, and feeling weak. Long-term thiamine deficiency can cause a serious condition called beriberi.

You get B vitamins from many foods, including leafy green vegetables, meats and fish, eggs, whole grains, milk, and other dairy products. A lack of vitamin B is rare in the United States, because many foods have added B vitamins. These foods include cereals, breads, and pasta.

Your results will show the amount of vitamin B1 (thiamine) that was tested. If your levels are normal but you still have symptoms, you may need other tests to find the cause.

If your thiamine level is low, your provider will look for the reason. Common causes include heavy alcohol use, malnutrition, or another long-term illness. You may need other tests to confirm the diagnosis.

Treatment usually involves taking thiamine supplements. In more serious cases, vitamins may be given by intravenous (IV) treatment.

If you have questions about your results, talk with your provider.