Certain enzymes present in fish and shellfish can destroy thiamine.
Signs of vitamin B1 deficiency
Insufficient dietary intake of thiamine can lead to deficiency. Certain other factors, like excessive alcohol intake and folic acid deficiency, can interfere with thiamine absorption and also result in deficiency.The most important manifestations of deficiency are weight loss, as well as problems with the heart and nervous system.
Deficiency can result in a condition known as beriberi. The disease is common in the developing world where rice is the major staple food and people consume raw fish (certain enzymes present in fish and shellfish can destroy thiamine).
Early symptoms of deficiency include fatigue, irritation, poor memory, sleep disturbances, pain in the chest, loss of appetite, abdominal discomfort and constipation.
Later, the disease presents itself in one of two forms: "dry" or "wet" beriberi.
Dry beriberi results in pins and needles in the toes, burning of the feet, calf muscle cramps and pains in the legs.
Beriberi involving the brain (Wernicke-Korsakoff syndrome) results when short-term severe deficiency is superimposed on chronic deficiency. The early stage is called Korsakoff syndrome, the signs of which range from mild confusion to coma.
Wernicke’s encephalopathy is the second part of the syndrome and results when beriberi involving the brain is not treated. Blood flow to the brain is decreased and coma and eventually death result.
Cardiovascular beriberi (wet beriberi) takes two forms. In the first form the person experiences a fast heart beat, sweating and the skin is warm. As the disease progresses, heart failure occurs.
The second form is called Shoshin disease and is very rare. In this case the onset of symptoms is sudden and overwhelming, and death through total cardiovascular collapse may occur in days or even hours.
(published with permission in writing from:http://www.health24.com)
