Diabetes

Vitamin D deficiency tied to gestational diabetes risk

(HealthDay)—Maternal vitamin D deficiency, as early as the first trimester of pregnancy, is associated with an increased risk for gestational diabetes mellitus (GDM), according to a study recently published in Diabetes, ...

Health

Melons are powerhouses in taste, nutrition

(HealthDay)—If you're looking for a tasty way to hydrate in warm weather, a juicy melon is the ticket. Melons are low-calorie, high-water content foods that also provide high doses of certain vitamins, minerals and important ...

Health

The top 5 veggies to add to your diet

(HealthDay)—The guidelines to eat more vegetables are clear, and eating a rainbow of colors gets you the widest variety of nutrients and phyto-nutrients, those hard-to-duplicate compounds that go beyond vitamins and minerals.

Alzheimer's disease & dementia

What helps prevent dementia? Try exercise, not vitamin pills

If you want to save your brain, focus on keeping the rest of your body well with exercise and healthy habits rather than popping vitamin pills, new guidelines for preventing dementia advise.

Health

Does sunscreen compromise vitamin D levels?

Sunscreen can reduce the sun's adverse effects, but there are concerns that it might inhibit the body's production of vitamin D. In a newBritish Journal of Dermatologystudy, however, investigators recorded an increase of ...

Health

A celebration salad fit for a queen or king

(HealthDay)—When you want to create a festive celebration without a fat and calorie overload, a seafood-based salad is the perfect choice. To step up the extravagance, make it with crabmeat.

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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