Vitamin A has a vital role in vision.
It is also known as retinol
. The retina is the light-sensitive layer at the back of the eye, and the rods and cone cells found here all use a derivative of retinol - retinal
, in conjunction with other compounds.
Vitamin A in the body can come from several dietary sources: esters, e.g. retinyl palmitate, which are simply hydrolysed in the digestive system, or via related carotenoid compounds, e.g. carotene, which require more processing.
The retinol molecule consists of a
side chain containing four double bonds
, and with an -OH (
at the end. This molecular structure - empirical formula C20H30O
- explains why retinol is fat soluble.
of describing retinol is "(