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 aand 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 iin 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 aand 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 pplants or eaten by animals. 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 oour 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 tthe 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. 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. LLarge 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 ...