A yellow, fat-soluble vitamin with a formula: C20H30O, present in fish oils and green vegetables, and essential to normal vision and to bone development
Vitamin A is a fat-soluble vitamin that has a beta-ionone ring where an isoprenoid chain is attached. The different forms of vitamin A include retinol or vitamin A1 and dehydroretinol.
Retinol (with a formula: C20H30O) is a form of vitamin A that is yellow in colour and typically occurs in tissues in a form of retinyl ester. It may also be available commercially as retinyl acetate or palmitate.1 Retinol can be obtained from food such as fish oils and green vegetables. One of its main biological functions is on vision. The retinol is converted into 11-cis-retinal in the presence of RPE65. It is then transported into the photoreceptor cells of the retina. Within these cells, the retinol switches on the visual cycle. Upon absorption of light it isomerizes into all-trans retinal. This leads to the alteration of the configuration of the rhodopsin, which is the visual pigment used in low light levels. Thus, it enables night vision.
IUPAC name: (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-enyl)nona-2,4,6,8-tetraen-1-ol
1 Meschino Health. "Comprehensive Guide to Vitamin A" . Retrieved from []