|
Vitamins
A vitamin is an organic molecule (or a set of molecules closely related chemically, i.e. vitamers) that is an essential micronutrient that an organism needs in small quantities for the proper functioning of its metabolism. Essential nutrients cannot be synthesized in the organism, either at all or not in sufficient quantities, and therefore must be obtained through the diet. Vitamin C can be synthesized by some species but not by others; it is not a vitamin in the first instance but is in the second. The term ''vitamin'' does not include the three other groups of essential nutrients: minerals, essential fatty acids, and essential amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, there are eight vitamers of vitamin E: four tocopherols and four tocotrienols. Some sources list fourteen vitamins, by including choline, but major health organizations list thirteen: vitamin A (as all-''trans''-retinol, all-''trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cobalamin
Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. It is important in the normal functioning of the nervous system via its role in the synthesis of myelin, and in the circulatory system in the maturation of red blood cells in the bone marrow. Plants do not need cobalamin and carry out the reactions with enzymes that are not dependent on it. Vitamin B12 is the most chemically complex of all vitamins, and for humans, the only vitamin that must be sourced from animal-derived foods or from supplements. Only some archaea and bacteria can synthesize vitamin B12. Most people in developed countries get enough B12 from the consumption of meat or foods with animal sources. Foods containing vitamin B12 include meat, clams, liver, fish, poultry, eggs, and dairy products. Many breakfast cereals ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiamine
Thiamine, also known as thiamin and vitamin B1, is a vitamin, an essential micronutrient, that cannot be made in the body. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosphorylated forms of thiamine are required for some metabolic reactions, including the breakdown of glucose and amino acids. Food sources of thiamine include whole grains, legumes, and some meats and fish. Grain processing removes much of the vitamin content, so in many countries cereals and flours are enriched with thiamine. Supplements and medications are available to treat and prevent thiamine deficiency and disorders that result from it include beriberi and Wernicke encephalopathy. They are also used to treat maple syrup urine disease and Leigh syndrome. Supplements and medications are typically taken by mouth, but may also be given by intravenous or intramuscular injection. Thiamine supplements are generally well tolerated. Allergic reactions, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niacin (substance)
Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It can be manufactured by plants and animals from the amino acid tryptophan. Niacin is obtained in the diet from a variety of whole and processed foods, with highest contents in fortified packaged foods, meat, poultry, red fish such as tuna and salmon, lesser amounts in nuts, legumes and seeds. Niacin as a dietary supplement is used to treat pellagra, a disease caused by niacin deficiency. Signs and symptoms of pellagra include skin and mouth lesions, anemia, headaches, and tiredness. Many countries mandate its addition to wheat flour or other food grains, thereby reducing the risk of pellagra. The amide derivative nicotinamide (niacinamide) is a component of the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP+). Although niacin and nicotinamide are identical in their vitamin activity, nicotinam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folate
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and storage. Folate is required for the body to make DNA and RNA and metabolise amino acids necessary for cell division. As humans cannot make folate, it is required in the diet, making it an essential nutrient. It occurs naturally in many foods. The recommended adult daily intake of folate in the U.S. is 400 micrograms from foods or dietary supplements. Folate in the form of folic acid is used to treat anemia caused by folate deficiency. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in the baby. Low levels in early pregnancy are believed to be the cause of more than half of babies born with NTDs. More than 80 countries use either mandatory or voluntary fortification of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folic Acid
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing and storage. Folate is required for the body to make DNA and RNA and metabolise amino acids necessary for cell division. As humans cannot make folate, it is required in the diet, making it an essential nutrient. It occurs naturally in many foods. The recommended adult daily intake of folate in the U.S. is 400 micrograms from foods or dietary supplements. Folate in the form of folic acid is used to treat anemia caused by folate deficiency. Folic acid is also used as a supplement by women during pregnancy to reduce the risk of neural tube defects (NTDs) in the baby. Low levels in early pregnancy are believed to be the cause of more than half of babies born with NTDs. More than 80 countries use either mandatory or voluntary fortification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biotin
Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', borrowed from the German , derives from the Ancient Greek word (; 'life') and the suffix "-in" (a suffix used in chemistry usually to indicate 'forming'). Chemical description Biotin is classified as a heterocyclic compound, with a sulfur-containing ring fused ureido and tetrahydrothiophene group. A C5-carboxylic acid side chain is appended to one of the rings. The ureido ring, containing the −N−CO−N− group, serves as the carbon dioxide carrier in carboxylation reactions. Biotin is a coenzyme for five carboxylase enzymes, which are involved in the catabolism of amino acids and fatty acids, synthesis of fatty acids, and gluconeogenesis. Biotinylation of histone proteins in nuclear chromatin plays a role in chromatin stability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riboflavin
Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in energy metabolism, cellular respiration, and antibody production, as well as normal growth and development. The coenzymes are also required for the metabolism of niacin, vitamin B6, and folate. Riboflavin is prescribed to treat corneal thinning, and taken orally, may reduce the incidence of migraine headaches in adults. Riboflavin deficiency is rare and is usually accompanied by deficiencies of other vitamins and nutrients. It may be prevented or treated by oral supplements or by injections. As a water-soluble vitamin, any riboflavin consumed in excess of nutritional requirements is not stored; it is either not absorbed or is absorbed and quickly excreted in urine, causing the urine to have a bright yellow tint. Natural sources of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pantothenic Acid
Pantothenic acid, also called vitamin B5 is a water-soluble B vitamin and therefore an essential nutrient. All animals require pantothenic acid in order to synthesize coenzyme A (CoA) – essential for fatty acid metabolism – as well as to, in general, synthesize and metabolize proteins, carbohydrates, and fats. Pantothenic acid is the combination of pantoic acid and β-alanine. Its name derives from the Greek ''pantos'', meaning "from everywhere", as minimally, at least small quantities of pantothenic acid are found in nearly every food. Human deficiency is very rare. As a dietary supplement or animal feed ingredient, the form commonly used is calcium pantothenate because of chemical stability, and hence long product shelf life, compared to sodium pantothenate or free pantothenic acid. Definition Pantothenic acid is a water-soluble vitamin, one of the B vitamins. It is synthesized from the amino acid β-alanine and pantoic acid (see biosynthesis and structure of coen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin E
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E, can cause nerve problems. Vitamin E is a fat-soluble antioxidant which may help protect cell membranes from reactive oxygen species. Worldwide, government organizations recommend adults consume in the range of 3 to 15 mg per day. As of 2016, consumption was below recommendations according to a worldwide summary of more than one hundred studies that reported a median dietary intake of 6.2 mg per day for alpha-tocopherol. Population studies suggested that people who consumed foods with more vitamin E, or who chose on their own to consume a vitamin E dietary supplement, had lower incidence of cardiovascular diseases, cancer, dementia, and other diseases. However, placebo-controlled clinical trials using alpha-tocopherol as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitamin D
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 ( cholecalciferol) and vitamin D2 ( ergocalciferol). The major natural source of the vitamin is synthesis of cholecalciferol in the lower layers of epidermis of the skin through a chemical reaction that is dependent on sun exposure (specifically UVB radiation). Cholecalciferol and ergocalciferol can be ingested from the diet and supplements. Only a few foods, such as the flesh of fatty fish, naturally contain significant amounts of vitamin D. In the U.S. and other countries, cow's milk and plant-derived milk substitutes are fortified with vitamin D, as are many breakfast cereals. Mushrooms exposed to ultraviolet light contribute useful amounts of vitamin D2. Dietary recommendations typically assume that all of a person's vitamin D is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tocopherol
Tocopherols (; TCP) are a class of organic chemical compounds (more precisely, various methylated phenols), many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named ''tocopherol'', from Greek τόκος ''tókos'' 'birth' and φέρειν ''phérein'' 'to bear or carry', that is 'to carry a pregnancy', with the ending ''-ol'' signifying its status as a chemical alcohol. α-Tocopherol is the main source found in supplements and in the European diet, where the main dietary sources are olive and sunflower oils, while γ-tocopherol is the most common form in the American diet due to a higher intake of soybean and corn oil. Tocotrienols, which are related compounds, also have vitamin E activity. All of these various derivatives with vitamin activity may correctly be referred to as " vitamin E". Tocopherols and tocotrienols are fat-soluble antioxidants but also seem to have many other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Nutrient
A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures, such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products ( ethanol or vinegar), leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_space_filling_model.jpg "Click for more on -> Niacin (substance)")
