Ex. 19. Speak on the vitamins.

Ex. 20. Read the following text and entitle it:

Vitamins are compounds that you must have to growth and health. They are needed in small amounts only and are usually available in the foods that you eat. Vitamin A is necessary for normal growth and health and for healthy eyes and skin. Lack of vitamin A may lead to a rare condition called night blindness (problems seeing in the dark), as well as dry eyes, eye infections, skin problems, and slowed growth. Your physician may treat these problems by prescribing vitamin A for you. Vitamin A is found in various foods including yellow-orange fruits and vegetables; dark green, leafy vegetables; whole milk; and margarine. Vitamin A comes in different forms. The form of vitamin A found in plants is called beta-carotene. Food processing may destroy some of the vitamins. For example freezing may reduce the amount of vitamin A in foods. Vitamin A is stored in the body and taking too much over a period of time can cause poisoning.

Vitamin B₂ (riboflavin) is necessary for normal metabolism. Lack of vitamin B₂ may lead to itching and burning eyes, sensitivity of eyes to light, sore tongue, itching skin on the nose, and sores in the mouth. Vitamin B₂ is found in various foods, including milk and dairy products, fish, meat, green leafy vegetables, and whole grain and enriched cereals and bread.

Vitamin B₁₂ is necessary for healthy blood. Cyanocobalamin and hydroxocobalamin are man-made forms of vitamin B₁₂. Lack of vitamin B₁₂ may lead to anemia, stomach problems, and nerve damage. Vitamin B₁₂ is found in various foods, including fish, egg yolk, milk, and fermented cheeses. It is not found in any vegetables.

Vitamin E prevents a chemical reaction called oxidation, which can sometimes result in harmful effects in the human body. Lack of vitamin E is extremely rare, except in people who have a disease in which it is not absorbed into the body. Vitamin E is found in various foods including vegetable oils (corn, soybean), wheat germ, whole-grain cereals, and green leafy vegetables. Vitamin E is stored in the body and taking too much over a period of time may cause harmful effects.

Vitamin K is necessary for normal clotting of the blood. Vitamin K is found in various foods including green leafy vegetables, meat, and dairy products. If you eat a balanced diet containing these foods, you should be getting all the vitamin K you need. Little vitamin K is lost from foods with ordinary cooking. Lack of vitamin K is rare but may lead to problems with blood clotting and increased bleeding. Vitamin K is routinely given to newborn infants to prevent bleeding problems. It is found in spinach, vegetable oils, and cabbage.

Vitamin D is necessary for strong bones and teeth. Lack of vitamin D may lead to a condition called rickets, especially in children, in which bones and teeth are weak. In adults it may cause a condition called osteomalacia, in which calcium is lost from bones so that they become weak. Vitamin D is sometimes used to treat other diseases in which calcium is not used properly by the body. Vitamin D is found naturally only in fish and fish-liver oils. However, it is also found in other foods such as milk and bread to which it has been added. Cooking does not affect the vitamin D in foods. Vitamin D is sometimes called the “sunshine vitamin” since it is made in the skin when the human is exposed to sunlight. If you eat a balanced diet and get outside in the sunshine, you should be getting all the vitamin D you need.

Date: 2015-12-17; view: 754