Thiamine, also known as vitamin B1, is a water-soluble vitamin crucial for energy metabolism. It plays a vital role as a coenzyme in the decarboxylation of α-keto acids, such as pyruvate, and in the conversion of carbohydrates into energy. Thiamine is involved in the pentose phosphate pathway, which is essential for nucleic acid and amino acid synthesis. It also supports the nervous system by participating in the synthesis of neurotransmitters, such as acetylcholine. Without adequate thiamine, the body cannot efficiently generate ATP, the primary energy source. A deficiency of thiamine can result in conditions like beriberi, which manifests as weakness, nerve damage, and cardiovascular issues. Another disorder related to thiamine deficiency is Wernicke-Korsakoff syndrome, commonly seen in alcoholics, characterized by neurological symptoms such as confusion, memory loss, and difficulty with muscle coordination. The dietary requirement of thiamine varies with age, sex, and physiological conditions like pregnancy or lactation.