News tagged with vitamin

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Obese people need more vitamin E, but actually get less

A recent study suggests that obese people with metabolic syndrome face an unexpected quandary when it comes to vitamin E - they need more than normal levels of the vitamin because their weight and other problems are causing ...

Nov 02, 2015
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Increasing vitamin D supplementation

Elderly women should take in more vitamin D than previously recommended during the winter months. This is the finding of a new study just released by a team of researchers led by ETH Professor Michael B. Zimmermann.

Nov 02, 2015
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Divided opinions on vitamin D enrichment

Vitamin D is important for the absorption and metabolism of calcium, as well as for maintaining healthy bones and muscles. Danes generally have too low a level, and this is mainly because the sun - the main source - is absent ...

Oct 26, 2015
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Vitamin B3 derivative cuts risk of new skin cancers

A year of treatment with nicotinamide, a form of vitamin B3, significantly lowered the risk of common, non-melanoma skin cancer in high-risk patients, according to University of Sydney research published today in the New ...

Oct 21, 2015
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Get more out of your vitamin D

If you take a vitamin D pill to meet your requirements for the sunshine vitamin, you'll get more out of it if you eat it with a little fat. Fat stimulates the release of bile into the small intestine, which makes it easier ...

Oct 14, 2015
popularity54 comments 0


A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. A compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on the circumstances and the particular organism. For example, ascorbic acid functions as vitamin C for some animals but not others, and vitamins D and K are required in the human diet only in certain circumstances. The term vitamin does not include other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids, nor does it encompass the large number of other nutrients that promote health but are otherwise required less often.

Vitamins are classified by their biological and chemical activity, not their structure. Thus, each "vitamin" may refer to several vitamer compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals are grouped under an alphabetized vitamin "generic descriptor" title, such as "vitamin A," which includes the compounds retinal, retinol, and many carotenoids. Vitamers are often inter-converted in the body.

Vitamins have diverse biochemical functions, including function as hormones (e.g. vitamin D), antioxidants (e.g. vitamin E), and mediators of cell signaling and regulators of cell and tissue growth and differentiation (e.g. vitamin A). The largest number of vitamins (e.g. B complex vitamins) function as precursors for enzyme cofactor bio-molecules (coenzymes), that help act as catalysts and substrates in metabolism. When acting as part of a catalyst, vitamins are bound to enzymes and are called prosthetic groups. For example, biotin is part of enzymes involved in making fatty acids. Vitamins also act as coenzymes to carry chemical groups between enzymes. For example, folic acid carries various forms of carbon group – methyl, formyl and methylene - in the cell. Although these roles in assisting enzyme reactions are vitamins' best-known function, the other vitamin functions are equally important.

Until the 1900s, vitamins were obtained solely through food intake, and changes in diet (which, for example, could occur during a particular growing season) can alter the types and amounts of vitamins ingested. Vitamins have been produced as commodity chemicals and made widely available as inexpensive pills for several decades, allowing supplementation of the dietary intake.

This text uses material from Wikipedia, licensed under CC BY-SA

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