Vitamin A is the earliest vitamin being discovered. There are two types of Vitamin A: one is retinol which is the initial form of VA, it only exists in animals; another one is carotene. Retinol can be composited by β-carotene coming from plants. Inside the body, under the catalysis of β-carotene-15 and 15′-double oxygenase, β-carotene is transformed into ratinal which is returned to retinol by the performance of ratinal reductase. Thus β-carotene is also called as vitamin precursor.
Vitamin A is a group of unsaturated nutritional organic compounds, that includes several provitamin A carotenoids, among which beta-carotene is the most important.
Application:
Prevent night blindness and vision loss; it’s helpful to the treatment of eye diseases. (VA could promote the formation of photo pigment inside eyes)
