Health

Niacin to boost your HDL 'good' cholesterol

Niacin is an important B vitamin that may raise your HDL, ("good"), cholesterol. Find out if you should talk to your health care provider about taking niacin alone or with cholesterol medications.

Oncology & Cancer

Vitamin D supplements may reduce risk of developing advanced cancer

For many years, investigators have been trying to pin down the tantalizing connection between vitamin D and cancer. Epidemiological studies have found that people who live near the equator, where exposure to sunlight produces ...

Health

Targeted efforts do not alter outcomes in healthy elderly

(HealthDay)—In elderly adults, vitamin D supplementation, omega-3 supplementation, and strength training, individually or in combination, do not improve clinical outcomes, according to a study published in the Nov. 10 issue ...

Health

Time to add some sunshine (vitamin D) to milk and bread

Free vitamin D supplements will be sent to over 2 million clinically vulnerable people in England this winter. Over 80% of patients hospitalized with COVID-19 are vitamin D deficient compared with the general population. ...

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Vitamin

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