A white crystalline compound of the vitamin-B complex (C₁₂H₁₇N₄OS)C1 essential to the normal functioning of the nervous system, found in many foods, as peas, cereals, liver, etc; vitamin B.

硫胺素；维他命B1(神经系统的正常运作所必需的维生素，可自豆、谷、肝等食物中取得)。化学式为 (C₁₂H₁₇N₄OS)C1。