Retinol

Retinol is one of the animal forms of vitamin A. It is a diterpenoid and an alcohol. It is convertible to other forms of vitamin A, and the retinyl ester derivative of the alcohol serves as the storage form of the vitamin in animals.

When converted to the retinal (retinaldehyde) form, vitamin A is essential for vision, and when converted to retinoic acid is essential for skin health, teeth remineralization and bone growth. These chemical compounds are collectively known as retinoids, and possess the structural motif of all-trans retinol as a common feature in their structure. Structurally, all retinoids also possess a β-ionone ring and a polyunsaturated side chain, with either an alcohol, aldehyde, a carboxylic acid group or an ester group. The side chain is composed of four isoprenoid units, with a series of conjugated double bonds which may exist in trans- or cis-configuration.