Thiamine (vitamin B₁) is a type of B vitamin. It is not stored in the body. People must replenish the vitamin in their body every day. It works with the other B vitamins to help the body convert food (carbohydrates) into fuel (glucose), which is used to produce energy. Thiamine is found in both plants and animals and plays a crucial role in certain metabolic reactions. The body needs it to form adenosine triphosphate (ATP), which every cell of the body uses for energy. Like other B complex vitamins, thiamine is sometimes called an "anti-stress" vitamin because it may strengthen the immune system and improve the body's ability to withstand stressful conditions.