In the early 20th century the discovery of vitamins began.

Today thereis a chance that there are some vitamins that are still undiscovered. Thedefinition of vitamin is: one of several substances necessary for animalnutrition, and occurring in minute quantities in natural foods; numerous typeshave been distinguished, and designated by the letters of the alphabet. Eachand every living animal needs vitamins to grow and be healthy.Since the human body can t produce vitamins naturally or normallyproduce the amounts needed, food provides the body with them. There aredifferent vitamins found in different foods. These vitamins give vitalnutrients to an animal.

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In 1906, the British biochemist Sir. Frederick Hopkins demonstrated thatfoods contain accessory factors in addition to proteins, carbohydrates, fats,minerals and water. Then, in 1912, thee chemist Casimir Funk identified thatthe antiberiberi substance in unpolished rice was an amine (a type ofNitrogen-containing compound), so Funk proposed that it be named vitamine, fromvital amine.

It was later discovered that different vitamins have differentchemical properties. This discovery caused vitamine to be turned into vitamin.In 1912 Hopkins and Funk made a hypothesis. The hypothesis stated theabsence of some vitamins could cause diseases such as beriberi and scurvy.Later a letter was assigned to each vitamin. The letters which were assigned tovitamins in the early years of vitamin research categorize them according totheir functions.

As research progressed, the vitamins were given scientificnames.Foods that contain vitamins are very essential for good health andgrowth. Milk can be important because it is a source of vitamin D. Vitamin Dis important because it is essential for bone growth.Butter can be important because it is a source of Vitamin A.

Thepigments that are converted into Vitamin A, are found in most fruits andvegetables. Vitamin A is important because it can prevent diseases.Cereal and seeds can de important because of its source of Vitamin B.Vitamin B is important because of their source of Vitamin B.

Vitamin B isimportant because it can prevent beriberi.Citrus Fruits can be important because of their source of vitamin C.Vitamin C is important for strength and metabolism.Plants can be important because of the plant oil which is a source ofVitamin E.

Vitamin e is important because it is a source of oxidation in bodytissues.These examples prove that the distribution of vitamins in naturalsources is uneven. Take vitamin D for example. It is produced only by animals,where as some other vitamins may only be found in plants. Vitamins can besynthetically produced or found naturally, but there is no proof that eithernatural or synthetic vitamins are superior to one another.There are two categories of vitamins needed in the human body. Thefirst are water-soluble vitamins, like B and C.

The second category is fat-soluble vitamins, such as vitamins A, D, E, and K. Water-soluble vitamins areabsorbed by the intestine. Once the intestine absorbs them, the circulatorysystem carries them to certain tissues.

Fat-soluble vitamins are also absorbed by the intestine, and the lymphsystem carries the vitamins to the various parts of the body. These vitaminsare responsible for maintaining the structure of the cell membranes.Don t think that you can have as many vitamins as you want. If too manyvitamins are taken into the body, the vitamin levels in the body become toxic.Since the body can’t produce the essential amounts of vitamins, theremust be a certain requirement of intake of vitamins and vitamin supplements.These requirements are known as the recommended daily allowance, or RDA.

Ifthese requirements aren’t met, you can become a very unhealthy person. The foodand Nutrition Board of the National Academy of Science/National Research Councilin the United States establishes these RDA s. For different worldwidepopulation groups two agencies of the United Nation, the Food and AgricultureOrganization and the World Health Organization have developed RDA s.It is wise to follow the RDA. Without correct interpretation of the RDA,a person could take too many or take too few vitamins.

This proves thatvitamins can be beneficial of harmful depending on the usage.Category: Science


Vitamins Vitamin, any of the organic compounds required by the body in small amounts for metabolism, to protect health, and for proper growth in children. Vitamins also assist in the formation of hormones, blood cells, nervous-system chemicals, and genetic material. The various vitamins are not chemically related, and most differ in their physiological actions.

They generally act as catalysts, combining with proteins to create metabolically active enzymes that in turn produce hundreds of important chemical reactions throughout the body. Without vitamins, many of these reactions would slow down or cease.The intricate ways in which vitamins act on the body, however, are still far from clear. The 13 well-identified vitamins are classified according to their ability to be absorbed in fat or water. The fat-soluble vitamins-A, D, E, and K-are generally consumed along with fat-containing foods, and because they can be stored in the body’s fat, they do not have to be consumed every day. The water-soluble vitamins-the eight B vitamins and vitamin C-cannot be stored and must be consumed frequently, preferably every day (with the exception of some B vitamins, as noted below).

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The body can manufacture only vitamin D; all others must be derived from the diet. Lack of them causes a wide range of metabolic and other dysfunctions. In the U.S., since 1940, the Food and Nutrition Board of the National Research Council has published recommended dietary allowances (RDA) for vitamins, minerals, and other nutrients.Expressed in milligrams or international units (IU) for adults and children of normal health, these recommendations are useful guidelines not only for professionals in nutrition but also for the growing number of families and individuals who eat irregular meals and rely on prepared foods, many of which are now required to carry nutritional labeling. A well-balanced diet contains all the necessary vitamins, and most individuals who follow such a diet can correct any previous vitamin deficiencies. However, persons who are on special diets, who are suffering from intestinal disorders that prevent normal absorption of nutrients, or who are pregnant or lactating may need particular vitamin supplements to bolster their metabolism.

Beyond such real needs, vitamin supplements are also often popularly believed to offer cures for many diseases, from colds to cancer; but in fact the body quickly eliminates most of these preparations without absorbing them. In addition, the fat-soluble vitamins can block the effect of other vitamins and even cause severe poisoning when taken in excess.Vitamin A Vitamin A is a pale yellow primary alcohol derived from carotene. It affects the formation and maintenance of skin, mucous membranes, bones, and teeth; vision; and reproduction. An early deficiency symptom is night blindness (difficulty in adapting to darkness); other symptoms are excessive skin dryness; lack of mucous membrane secretion, causing susceptibility to bacterial invasion; and dryness of the eyes due to a malfunctioning of the tear glands, a major cause of blindness in children in developing countries. The body obtains vitamin A in two ways.

One is by manufacturing it from carotene, a vitamin precursor found in such vegetables as carrots, broccoli, squash, spinach, kale, and sweet potatoes. The other is by absorbing ready-made vitamin A from plant-eating organisms. In animal form, vitamin A is found in milk, butter, cheese, egg yolk, liver, and fish-liver oil.Although one-third of American children are believed to consume less than the recommended allowance of vitamin A, sufficient amounts can be obtained in a normally balanced diet rather than through supplements. Excess vitamin A can interfere with growth, stop menstruation, damage red blood corpuscles, and cause skin rashes, headaches, nausea, and jaundice.

The B Vitamins Known also as vitamin B complex, these are fragile, water-soluble substances, several of which are particularly important to carbohydrate metabolism. B1 Thiamine, or vitamin B1, a colorless, crystalline substance, acts as a catalyst in carbohydrate metabolism, enabling pyruvic acid to be absorbed and carbohydrates to release their energy. Thiamine also plays a role in the synthesis of nerve-regulating substances. Deficiency in thiamine causes beriberi, which is characterized by muscular weakness, swelling of the heart, and leg cramps and may, in severe cases, lead to heart failure and death.

Many foods contain thiamine, but few supply it in concentrated amounts. Foods richest in thiamine are pork, organ meats (liver, heart, and kidney), brewer’s yeast, lean meats, eggs, leafy green vegetables, whole or enriched cereals, wheat germ, berries, nuts, and legumes. Milling of cereal removes those portions of the grain richest in thiamine; consequently, white flour and polished white rice may be lacking in the vitamin. Widespread enrichment of flour and cereal products has largely eliminated the risk of thiamine deficiency, although it still occurs today in nutritionally deficient alcoholics. B2 Riboflavin, or vitamin B2, like thiamine, serves as a coenzyme-one that must combine with a portion of another enzyme to be effective-in the metabolism of carbohydrates, fats, and, especially, respiratory proteins. It also serves in the maintenance of mucous membranes.Riboflavin deficiency may be complicated by a deficiency of other B vitamins; its symptoms, which are not as definite as those of a lack of thiamine, are skin lesions, especially around the nose and lips, and sensitivity to light.

The best sources of riboflavin are liver, milk, meat, dark green vegetables, whole grain and enriched cereals, pasta, bread, and mushrooms. B3 Niacin, also known as nicotinic acid and vitamin B3, also works as a coenzyme in the release of energy from nutrients. A deficiency of niacin causes pellagra, the first symptom of which is a sunburnlike eruption that breaks out where the skin is exposed to sunlight. Later symptoms are a red and swollen tongue, diarrhea, mental confusion, irritability, and, when the central nervous system is affected, depression and mental disturbances. The best sources of niacin are liver, poultry, meat, canned tuna and salmon, whole grain and enriched cereals, dried beans and peas, and nuts. The body also makes niacin from the amino acid tryptophan. Megadoses of niacin have been used experimentally in the treatment of schizoph …


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