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1. Vitamin A deficiency is estimated to affect approximately one third of children under the age of five around the world.
2. Vitamin С is found in high concentrations in immune cells, and is consumed quickly during infections.
3. In modern Western societies, scurvy is rarely present in adults, although infants and elderly people may be affected.
4. A multivitamin is a preparation intended to supplement a human diet with vitamins, dietary minerals and other nutritional elements.
5. Wheat germ oil contains the four fatty acids which have been reported to lower plasma cholesterol in humans.
6. In their natural form whole-grain cereals are a rich source of vitamins, minerals, carbohydrates, fats, oils, and protein.
7. Cod liver oil is widely taken to ease the pain and joint stiffness associated with arthritis, and has also been clinically proven to have a positive effect on the heart, bones, skin, hair, and nails.
8. Soft cod liver can be tinned (canned) and eaten. It is an important source of vitamin A, vitamin D, vitamin E and omega-3 fatty acids.
9. Children and adults both require folic acid to produce healthy blood cells and prevent anaemia.
10. Rickets is among the most frequent childhood diseases in developing countries. The predominant cause is a vitamin D de: ciency, but lack of adequate calcium in the diet may also lead rickets.
VITAMINS
A vitamin is an organic compound required as a nutrient in sr amounts by an organism. Vitamins regulate chemical reactions which the body converts food into energy and living tissues. They are essential nutrients for the healthy maintenance of the cells, tissi and organs that make up a multicellular organism.
Vitamins are classified as either water-soluble or fat-soluble, humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and water-soluble (8 В vitamins and vitamin C). Water-soluble vitar dissolve easily in water and are readily excreted from the body with tr urine. Because they are not readily stored, consistent daily intake important. Fat-soluble vitamins are absorbed through the intesti tract with the help of lipids and are more likely to accumulate in body.
Vitamin A (retinol) is necessary for healthy skin, development the bones, and good vision. Sources of this vitamin include cod In oil, yellow, orange and green vegetables, and milk.
Vitamin B1, also called thiamine, is necessary for changing starcl and sugars into energy. It is found in meat and whole-grain cereals, ric
Vitamin B2 or riboflavin is essential for complicated chemical reactions that take place during the body's use of food. Milk, cheese, fish, liver, meat, eggs and green vegetables supply vitamin B2.
Vitamin B3 is better known as niacin or vitamin PP. Cells nee niacin in order to release energy from carbohydrates. Liver, yeast, lea meat, fish, nuts, and legumes contain niacin.
Vitamins B5 (pantothenic acid), B6 (pyridoxine) and B7 (biotin) all play a role in chemical reactions in the body. Many foods contain small amounts of these vitamins, but mainly meat, dairy products, eggs and whole-grain cereals.
Vitamins B12 or cobalamin and B9 (also called folate, folic acid or folacin) are both needed for forming red blood cells and for a healthy nervous system. Vitamin B12 is found in animal products, especially liver. Folate is present in green leafy vegetables.
Vitamin С or ascorbic acid is necessary for the maintenance of the ligaments, tendons, and other supportive tissue. It is considered to be the main immune vitamin. It is found in fruits, especially in kiwifruits, oranges and lemons.
Vitamin D or calciferol is necessary for the body's use of calcium. It is present in cod liver oil and vitamin D -fortified milk.
Vitamin E or tocopherol helps maintain cell membranes. It is one of the known antioxidants. Unrefined vegetable oils, especially wheat germ oil, and whole-grain cereals are especially rich in this vitamin. It is also found in small amounts in most meats, fruits, and vegetables.
Vitamin К (К1 — phylloquinone and К2 — menaquinone) is necessary for proper clotting of the blood. Green leafy vegetables contain vitamin K.
Hence, for the most part, vitamins are obtained with food, but a few are obtained by other means. For example, microorganisms in the intestine — commonly known as 'gut flora' — produce vitamins К and B7 (biotin), while one form of vitamin D is synthesized in the skin with the help of the natural ultraviolet waves of sunlight.
Deficiencies of vitamins are classified as either primary or secondary. A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a 'lifestyle factor', such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin. People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency. In contrast, restrictive diets have the potential to cause prolonged vitamin deficiency, which may result in often painful and potentially deadly diseases, such as scurvy (vit С deficit), rickets (vit D), anaemia (vit B6) and others.
Avitaminosis is any disease caused by chronic or long-term vitamin deficiency or caused by a defect in metabolic conversion, such as tryptophan to niacin. Conversely hypervitaminosis is the syndrome caused by over-retention of fat-soluble vitamins in the body.
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