Friday, September 26, 2008

Vitamins in General

Vitamins in General
20th century marks the most exciting era in the history of nutrition science. It was during this time that the discovery of vitamins or “accessory growth factors,” began. Researchers found that for life and growth animals required something more than a chemically defined diet consisting of purified carbohydrate, protein, and aft, the essential mineral, and water.

The first of these dietary essentials discovered was and antiberiberi substance isolated from rice polishing by Funk, a Polish biochemist. Because the substance was an amine and necessary for life, Funk gave it the name vitamine. Very shortly thereafter McCollum and Davis extracted a factor from butter fat that they called fat soluble A to distinguish it from the water soluble antiberiberi substance. These two essential factors became known as vitamine A and vitamine B. As each additional vitamin was discovered, it was assigned a letter; the e on vitamine was dropped to give the general name vitamin because only a few of the essential substances were found to be amines.

As the chemical structure of the vitamin became known through its isolation and synthesis; it was given a chemical name. When the chemical name was assigned, it was assumed that the name applied to one substance with one specific activity. Now it is evident that a vitamin may have a variety of functions and that vitamin activity may be found in several closely related compounds known as vitamers. An excellent example of this is vitamin A, which has several seemly unrelated functions and encompasses not only retinol but also retinal and retinoic acid.
Vitamins in General