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(1) Vitamin C is also called ascorbic acid. It dissolves in water. It is found in fresh fruits, berries and green vegetables. Vitamin C helps wounds heal. Lack of vitamin C can cause a sickness called scurvy, a form of avitaminosis that is characterized by loose teeth, hemorrhages into muscles of the extremities and into joints, superficial bleeding, and fragility of blood vessels, compromised immunity, and anemia. Lack of Vitamin C was a serious health problem on long ocean trips where supplies of fresh fruit were quickly used up. Many people died from scurvy on such trips. Vitamin C was first found in 1928, and in 1932 it was proved to stop scurvy. Now scurvy occurs for the most part in city areas where very poor people live.
(2) Citrus fruits (such as lime, lemon, orange, and grapefruit) are good sources of vitamin C. Other foods that are good sources of vitamin C include papaya, broccoli, Brussels sprouts, blackcurrants, strawberries, cauliflower, spinach, green peppers, and kiwifruit. The amount of vitamin C in foods of plant origin depends on the kind of plant, the kind of soil where it grew, how much rain and sun it got, the length of time since it was picked, and how it was stored since then. Cooking food destroys vitamin C. Most species of animals synthesize their own vitamin C. It is therefore not a vitamin for them. Synthesis is achieved through a sequence of enzyme driven steps, which convert glucose to ascorbic acid. It is carried out either in the kidneys or the liver. It was only realized in the 1920s that some cuts of meat and fish are also a source of vitamin C for humans. The muscle and fat that make up the modern western diet are however poor sources.
(3) As a participant in hydroxylation, vitamin C is needed for the production of collagen in the connective tissue. These fibers are in many places throughout the body; providing firm but flexible structure. Some tissues have a greater percentage of collagen, especially: skin, mucous membranes, teeth, and bones. Vitamin C is required for making of dopamine, noradrenaline, and adrenaline in the nervous system or in the adrenal glands. Vitamin C is also needed to make carnitine, important in the transfer of energy to the cell mitochondria. It is a strong antioxidant. The tissues with greatest percentage of vitamin C—over 100 times the level in blood plasma—are the adrenal glands, pituitary, thymus, corpus luteum, and retina.
(4) A healthy person on a balanced western diet should be able to get all the vitamin C needed to prevent the symptoms of scurvy from their daily diet. People who smoke, those under stress and women in pregnancy have a slightly higher requirement. Vitamin C has a reputation for being useful in the treatment of colds and flu. The amount of vitamin C needed to avoid deficiency symptoms and maintain health has been set by various national agencies as follows: 40 mg per day (UK Food Standards Agency), 60-95 mg per day (US Food and Nutrition Board).
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