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(ЧТО ТАКОЕ АВИТАМИНОЗ?)
Vafin Ramil 10-12 group (Murzina G.A.)
Avitaminosis is the term used for a group of conditions or diseases caused by the chronic or long-term deficiency of one or more vitamins. Vitamins are substances that play various important roles in the growth and development of every human being. There are many kinds of vitamins, among them are Vitamin A, Vitamin C, and Vitamin B, and each one performs different actions inside the body. The manifestation of symptoms usually depends on the kind of vitamin deficiency an individual has. Examples of conditions associated with avitaminosis are pellagra, beriberi, scurvy, rickets, and night blindness.
Pellagra occurs when a person does not consume sufficient amount of niacin in his diet. Niacin or Vitamin B3 is essential for the proper functioning of the nerves, digestive system and the skin. This disease is sometimes called the disease with four Ds because its major symptoms often include diarrhea, dermatitis, dementia — a disease affecting the mental ability of a person — and sometimes death. Other symptoms include rashes, mouth ulcers, vomiting, and tremors.
Niacin is found in variety of foods, including liver, chicken, beef, fish, cereal, peanuts and legumes, and is also synthesized from tryptophan, which is found in meat, dairy and eggs.
Beriberi is a condition caused by deficient intake of Vitamin B1 or thiamine. There are two types of beriberi — wet and dry beriberi. Wet beriberi affects the cardiovascular system and dry beriberi affects the nervous system. This type of avitaminosis is commonly seen in individuals who abuse alcohol. Symptoms include pain and swelling of the legs and feet, increased heart rate, tingling sensations, and wasting of the leg muscles.
Thiamine is found in a wide variety of foods at low concentrations. Yeast, yeast extract (e.g. Marmite) and pork are the most highly concentrated sources of thiamine. In general, cereal grains are the most important dietary sources of thiamine, by virtue of their ubiquity. Of these, whole grains contain more thiamine than refined grains, as thiamine is found mostly in the outer layers of the grain and in the germ (which are removed during the refining process).
Scurvy is a disease caused by the long-time deficiency of ascorbic acid or vitamin C. It is characterized by body weakness, inflammation of the gums, anemia, tender joints, and hemorrhages on the skin. There are several groups of individuals who are at high risk for the development of scurvy. These include alcoholics, elderly, children, and patients with mental problems.
The best sources that contain vitamin C are citrus fruits.
Rickets is a nutritional disorder caused by the deficiency of Vitamin D, which controls the production of calcium and phosphate being used by the body. This form of avitaminosis often results in the softening and weakening of the bones of affected children. Children and adults who usually stay indoors have a higher risk of developing Vitamin D deficiency because exposure to sunlight is often needed for its production.
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