Nutritional disorder, with nerve and heart impairment, caused by thiamin deficiency. Its name is from the Sinhalese word for “extreme weakness.” Symptoms include fatigue, digestive problems, and limb numbness and weakness. Dry beriberi involves gradual long-nerve degeneration, with muscle atrophy and loss of reflexes. Wet beriberi is more acute, with edema from cardiac failure and poor circulation. Thiamin occurs widely in food but is lost in processing; a well-balanced diet high in unprocessed foods can prevent beriberi. In Western countries, chronic alcoholism is the most common cause.

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Organic compound, part of the vitamin B complex, necessary in carbohydrate metabolism. It carries out these functions in its active form, as a component of the coenzyme thiamin pyrophosphate. Its molecular structure includes a substituted pyridine ring and a thiazole ring. Thiamin is found most abundantly in whole cereal grains and certain other seeds. Deficiency leads to beriberi.

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