Saturday, August 22, 2009
Food Sources of Vitamin A
Vitamin A, commonly known as retinol, is a group of fat-soluble vitamins, that play a crucial role in the smooth operation of many life-sustaining processes. It was discovered in 1917, through the independent efforts of Elmer McCollum at the University of Wisconsin-Madison, and Lafayette Mendel and Thomas Osborne at Yale University. Vitamins are generally classified as water-soluble and fat-soluble. Vitamin A belongs to the latter group, and occurs in different forms. It can be found as alcohol (retinol), aldehyde (retinal), acid (retinoic acid) and also as ester (retinyl palmitate).