Dictionary of Human Evolution and Biology

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State of malnutrition caused by a reversible deficiency (or avitaminosis) of vitamin B1. In the infantile forms there is involvement of the heart and gastrointestinal tract, usually fatal unless vitamin supplemented. In the adult onset form there are two primary types, dry and wet. The symptoms of the dry type include symmetrical, ascending neuritis (weakness of lower limbs, progressing upward) with increasing skin sensitivity. In the wet type there is heart failure and edema. Both types can be fatal. The primary cause is a deficiency of thiamine (vitamin B1), which is required for carbohydrate metabolism, and essential for the breakdown of pyruvic acid. Beriberi is common in Asia where the milling process, or rice polishing, removes the fuzzy surface of the grain, where thiamine is located. Feeding humans and test animals (e.g. chickens) affected with beriberi with a concentrate made from rice polishings reverses the clinical symptoms. Although first described in SE. Asia in the nineteenth century, it was 1912 before Casimir Funk showed that beriberi in pigeons could be cured by the above process; in similar experiments he showed the reversibility of several such conditions, coining the term vitamines (vitamins) for the deficient substances. The condition was described in Pacific fishermen in the twentieth century, when they subsisted on raw fish (sushi) that contains an enzyme that binds with and inactivates thiamine. Thiamine is abundant in pork meat and the coats of cereal grains.

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From "Dictionary of Nursing and Individual Health Care"