Vitamin B1,also known as thiamin or Thiamine, is a vitamin found in food, and manufactured as a dietary supplement and medication. Among food sources are whole grains, legumes, and some meats and fish. Refined grains lose much of their thiamine and cereals and flours are enriched with thiamine in many countries. Supplements and medications are available to treat and prevent thiamine deficiency and disorders that result from it, including beriberi and Wernicke encephalopathy. Other uses include the treatment of maple syrup urine disease and Leigh disease. They are typically taken by mouth, but may also be given by intravenous or intramuscular injection.