Thiamine

Thiamine is vitamin B1. Thiamine acts as a coenzyme in the metabolism of the body. Deficiency of thiamine leads to beriberi, a disease affecting the heart and nervous system. The word "vitamin" was coined in 1911 by the Warsaw-born biochemist Casimir Funk (1884-1967). At the Lister Institute in London, Funk isolated a substance that prevented nerve inflammation (neuritis) in chickens raised on a diet deficient in that substance. He named the substance "vitamine" because he believed it was necessary to life and it was a chemical amine. The "e" at the end was later removed when it was recognized that vitamins need not be amines. The letters (A, B, C and so on) were assigned to the vitamins in the order of their discovery. The one exception was vitamin K which was assigned its "K" from "Koagulation" by the Danish researcher Henrik Dam. The vitamins include: {{}}Vitamin A: Retinol. Carotene compounds responsible for transmitting light sensation in the retina of the eye. Deficiency leads to night blindness. Beta carotene: An antioxidant which protects cells against oxidation damage that can lead to cancer. Beta carotene is converted, as needed, to vitamin A. Food sources of beta carotene include vegetables such as carrots, sweet potatoes, spinach and other leafy green vegetables; and fruit such as cantaloupes and apricots. Excessive carotene in the diet can temporarily yellow the skin, a condition called carotenemia, commonly seen in infants fed largely mushed carrots. Vitamin B2: Riboflavin, essential for the reactions of coenzymes. Deficiency causes inflammation of the lining of the mouth and skin. Vitamin B3: Niacin, an essential part of coenzymes of body metabolism. Deficiency causes inflammation of the skin, vagina, rectum and mouth, as well as mental slowing. Vitamin B6: Pyridoxine, a cofactor for enzymes. Deficiency leads to inflammation of the skin and mouth, nausea, vomiting, dizziness , weakness and anemia. Folate (folic acid): Folic acid is an important factor in nucleic acid synthesis (the genetic material). Folate deficiency leads to megaloblastic anemia. Vitamin B12: An essential factor in nucleic acid synthesis (the genetic material of all cells). Deficiency leads to megaloblastic anemia, as can be seen in pernicious anemia. Vitamin C: Ascorbic acid, important in the synthesis of collagen, the framework protein for tissues of the body. Deficiency leads to scurvy, characterized by fragile capillaries, poor wound healing, and bone deformity in children. Vitamin D: A steroid vitamin which promotes absorption and metabolism of calcium and phosphorus. Under normal conditions of sunlight exposure, no dietary supplementation is necessary because sunlight promotes adequate vitamin D synthesis in the skin. Deficiency can lead to osteomalacia in adults and bone deformity (rickets) in children. Vitamin E: Deficiency can lead to anemia. Vitamin K: An essential factor in the formation of blood clotting factors. Deficiency can lead to abnormal bleeding.

* * *

SYN: thiamin.

* * *

thi·a·mine 'thī-ə-mən, -.mēn also thi·a·min -mən n a vitamin C₁₂H₁₇N₄OSCl of the B complex that is an amino hydroxy quaternary ammonium water-soluble salt containing a thiazole ring and a pyrimidine ring, that occurs widely both free (as in the germs of cereals and hulls of grain) and combined (as in yeast and in animal tissues like liver, kidneys, and heart) but is usu. synthesized commercially, that functions in the body as a cocarboxylase and is essential for carbohydrate metabolism and for normal functioning of the nervous system, and that is used in nutrition (as in vitamin preparations and in enriching flour and bread) and in medicine called also vitamin B₁

* * *

thi·a·mine (thiґə-min) vitamin B_{1>, a heat-labile, water-soluble bicyclic compound comprising a substituted pyrimidine linked to a thiazole moiety. It is found particularly in pork, organ meats, legumes, nuts, and whole grain or enriched cereals and breads. The active form is} thiamine pyrophosphate (q.v.). Deficiency of the vitamin can result in beriberi and is a factor in alcoholic neuritis and Wernicke-Korsakoff syndrome. Written also thiamin.