Archive for December, 2009

Sources of Vitamin A

Vitamin A can be found in two principal forms in foods: * retinol, the form of vitamin A absorbed when eating animal food sources, is a yellow, fat-soluble substance. Since the pure alcohol form is unstable, the vitamin is found in tissues in a form of retinyl ester. It is also commercially produced and administered […]

Knowing Vitamin A

Vitamin A is a vitamin which is needed by the retina of the eye in the form of a specific metabolite, the light-absorbing molecule retinal. This molecule is absolutely necessary for both scotopic and color vision. Vitamin A also functions in a very different role, as an irreversibly oxidized form retinoic acid, which is an […]