Vitamins

Content

Intraduction......................3 p.
Vitamin A........................4 p.
Vitamin D........................4 p.
Vitamin E........................5 p.
Vitamin B complex...................5 p.
Vitamin C........................7 p.
Conclusion......................7 p.
Reference........................8 p.
Introduction
All living things, plant or animal, need vitamins for health, growth, and reproduction. Yet vitamins are not a source of calories and do not contribute significantly to body mass. The plant or animal uses vitamins as tools in processes that regulate chemical activities in the organism and that use basic food elements–carbohydrates, fats, and proteins–to form tissues and to produce energy.Vitamins can be used over annd over, and only tiny amounts are needed to replace those that are lost. Nevertheless, most vitamins are essential in the diet because the body does not produce enough of them or, in many cases, does not produce them at all.Thirteen different vitamins have been identified by nutritionists: A, eight B-complex vitamins, C, D, E, and K. Some substances, such as carnitine and choline, behave like vitamins but are made in adequate amounts in the human body.Vitamins were originally placed inn categories based on their function in the body and were given letter names. Later, as their chemical structures were revealed, they were also given chemical names. Today, both naming conventions are used. Vitamins fall into two categories: fat soluble an

nd water soluble. The fat-soluble vitamins — A, D, E, and K — dissolve in fat and can be stored in your body. The water-soluble vitamins — C and the B-complex vitamins (such as vitamins B6, B12, niacin, riboflavin, and folate) — need to dissolve in water before your body can absorb them. Because of this, your body can’t store these vitamins. Any vitamin C or B that your body doesn’t use as it passes through your system is lost (mostly when you pee). So you need a fresh supply of these vitamins every day. Whereas vitamins are organic substances (made by plants or animals), minerals are inorganic elements that come from the soil and water and are absorbed by plants or eaten by annimals. Your body needs larger amounts of some minerals, such as calcium, to grow and stay healthy. Other minerals like chromium, copper, iodine, iron, selenium, and zinc are called trace minerals because you only need very small amounts of them each day.
The point of this work is to study vitamins and to know more about. This topic I have chosen because vitamins is very important for us, because quantity of the right variuos vitamins is our health.

Content
Fat-soluble vitamins
Vitamin A
Vitamin A,

, also called retinol, is a fat-soluble vitamin that is readily destroyed upon exposure to heat, light, or air. The vitamin has a direct role in vision and is a component of a pigment present in the retina of the eye. It is essential for the proper functioning of most body organs and also affects the functioning of the immune system. Vitamin A deficiency results in various disorders that most commonly involve the eye and the epithelial tissues–the skin and the mucous membranes lining the internal body surfaces. An early symptom of vitamin A deficiency is the development of night blindness, and continued deficiency eventually results in loss of sight. If deficiency is prolonged, the skin may become dry and rough. Vitamin A deficiency may also result in defective bone and teeth formation. Excessive intake of vitamin A causes a toxic condition. The symptoms may include nausea, coarsening and loss of hair, drying and scaling of the skin, bone pain, fatigue, and drowsiness. There may also be blurred vision and headache in adults, and growth failure, enlargement of the liver, and nervous irritability in children. Vitamins were originally placed in categories based on their function in the body and were giiven letter names. Later, as their chemical structures were revealed, they were also given chemical names. Today, both naming conventions are used. Good sources of vitamin A are milk, eggs, liver, fortified cereals, darkly colored orange or green vegetables (such as carrots, sweet potatoes, pumpkin, and kale), and orange fruits such as cantaloupe, apricots, peaches, papayas, and mangos.
Vitamin D
Vitamin D is a fat-soluble compound essential for calcium metabolism in animals and therefore important for normal mineralization of bone and cartilage. The skin forms vitamin D when exposed to sunlight, but in some circumstances sunlight may lack sufficient amounts of ultraviolet rays to bring about adequate production of the vitamin. Deficiencies cause many biochemical and physiological imbalances. If uncorrected, faulty mineralization of bones and teeth causes rickets in growing children and osteomalacia (progressive loss of calcium and phosphorus from the bones) in adults. Common early symptoms of rickets include restlessness, profuse sweating, lack of muscle tone in the limbs and abdomen, and delay in learning to sit, crawl, and walk. Rickets may produce such conditions as bowlegs and knock-knees. Deficiency may also cause osteoporosis, a bone condition characterized by an increased tendency of the bones to fracture. Large doses of vitamin D are toxic, and symptoms include weakness, loss of appetite, nausea, vomiting, diarrhea, excessive thirst, and weight loss. This vitamin is unique — your body manufactures it when you get sunlight on your skin! You can also get vitamin D from egg yolks, fish oils, and fortified foods like milk.
Vitamin E
Vitamin E is a fat-soluble compound. The metabolic roles of this vitamin are poorly understood. Its primary role appears to be as an inhibitor of oxidation processes in body tissues. Deficiency is rare but may impair neuromuscular function. Although serious toxicity has not been attributed to large doses of vitamin E, adverse effects have been reported. Vitamin E is found in many foods, such as vegetable oils, nuts, and green leafy vegetables. Avocados, wheat germ, and whole grains are also good sources.
Vitamin K
Vitamin K is fat-soluble and essential for the synthesis of certain proteins necessary for the clotting of blood. Deficiency, though relatively uncommon, results in impaired clotting of the blood and internal bleeding. Dietary sources include the photosynthetic (green) parts of plants.
Water-soluble vitamins
Vitamin B complex
Vitamin B complex consists of several vitamins that are grouped together because of the loose similarities in their properties, distribution in natural sources, and physiological functions. All the B vitamins are soluble in water. Most of the B vitamins have been recognized as coenzymes, and they all appear to be essential in facilitating the metabolic processes of all forms of animal life. The complex includes B1 (thiamine), B2 (riboflavin), niacin (nicotinic acid), B6 (a group of related pyridines), B12 (cyanocobalamin), folic acid, pantothenic acid, and biotin. Vitamin B1, or thiamine, helps the body convert carbohydrates into energy and helps in the metabolism of proteins and fats. Vitamin B1 deficiency affects the functioning of gastrointestinal, cardiovascular, and peripheral nervous systems. Beriberi and Wernicke-Korsakoff syndrome (often seen in alcoholics) are the primary diseases related to thiamine deficiency. General symptoms of beriberi include loss of appetite and overall lassitude, digestive irregularities, and a feeling of numbness and weakness in the limbs and extremities. People get thiamin from many different foods, including fortified breads, cereals, and pasta; meat and fish; dried beans, soy foods, and peas; and whole grains like wheat germ. Vitamin B2, or riboflavin, is required to complete several reactions in the energy cycle. Reddening of the lips with cracks at the corners of the mouth, inflammation of the tongue, and a greasy, scaly inflammation of the skin are common symptoms of deficiency. Some of the best sources of riboflavin are meat, eggs, legumes (like peas and lentils), nuts, dairy products, green leafy vegetables, broccoli, asparagus, and fortified cereals. Niacin, or nicotinic acid (B3), helps the metabolism of carbohydrates. Prolonged deprivation leads to pellagra, a disease characterized by skin lesions, gastrointestinal disturbance, and nervous symptoms.You’ll find niacin in red meat, poultry, fish, fortified hot and cold cereals, and peanuts. A form of Vitamin B6 is a coenzyme for several enzyme systems involved in the metabolism of proteins, carbohydrates, and fats. No human disease has been found to be caused by a deficiency of this vitamin. Chronic use of large doses of vitamin B6 can create dependency and cause complications in the peripheral nervous system. Vitamin B12, or cyanocobalamin, is a complex crystalline compound that functions in all cells, but especially in those of the gastrointestinal tract, the nervous system, and the bone marrow. It is known to aid in the development of red blood cells in higher animals. Deficiency most commonly results in pernicious anemia. Vitamin B12 is found naturally in fish, red meat, poultry, milk, cheese, and eggs. It’s also added to some breakfast cereals. Folic acid is necessary for the synthesis of nucleic acids and the formation of red blood cells. Folic-acid deficiency most commonly causes folic-acid-deficiency anemia. Symptoms include gastrointestinal problems, such as sore tongue, cracks at the corners of the mouth, diarrhea, and ulceration of the stomach and intestines. Large doses of folic acid can cause convulsions and other nervous-system problems. Dried beans and other legumes, green leafy vegetables, asparagus, oranges and other citrus fruits, and poultry are good sources of this vitamin. So are fortified or enriched bread, noodles, and cereals. Pantothenic acid promotes a large number of metabolic reactions essential for the growth and well-being of animals. Deficiency in experimental animals leads to growth failure, skin lesions, and graying of the hair. A dietary deficiency severe enough to lead to clear-cut disease has not been described in humans. Biotin plays a role in metabolic processes that lead to the formation of fats and the utilization of carbon dioxide. Biotin deficiency results in anorexia, nausea, vomiting, inflammation of the tongue, pallor, depression, and dermatitis.
Vitamin C
Vitamin C, or ascorbic acid, is water-soluble and easily destroyed. It is essential in wound healing and in the formation of collagen, a protein important in the formation of healthy skin, tendons, bones, and supportive tissues. Deficiency results in defective collagen formation and is marked by joint pains, irritability, growth retardation, anemia, shortness of breath, and increased susceptibility to infection. Scurvy is the classic disease related to deficiency. Symptoms peculiar to infantile scurvy include swelling of the lower extremities, pain upon flexing them, and bone lesions. Excessive ascorbic-acid intake can cause kidney stones, gastrointestinal disturbances, and red-blood-cell destruction. You’ll find high levels of vitamin C in red berries, kiwi, red and green bell peppers, tomatoes, broccoli, spinach, and juices made from guava, grapefruit, and orange.
Concliusion
So, when I was writing this topic, I studied more about vitamins. Also I got to know where we could find special kind of the vitamins and what is the benefit for human organism. During this work, there were not troubles, except the big quantity of literature on this topic. It was hard to choose valuable and realizable information.
Reference
1. Internet:

http://www.cyber-north.com/vitamins/history.html

http://www.vivo.colostate.edu

http://www.netdoctor.co.uk/health_advice/facts/vitamins_which.htm

http://www.reutershealth.com/wellconnected/doc39.html

http://www.kidshealth.org/kid/stay_healthy/food/vitamin.html