Retinol is an active form of Vitamin A, a fat-soluble vitamin that is essential to vision and bone development. Sources of retinol include liver, whole milk and fortified foods. The body can also convert retinol to retinal and retinoic acids as found in carotene compounds. Retinol is also a topical compound used in treating acne and improving other forms of skin damage from aging and UV damage from the sun.

Vitamin A plays an important role in vision health. A deficiency of Vitamin A leads to night blindness, which is one of the first signs of deficiency. Similarly, Vitamin A plays an essential role in bone health and nourishment. However, an excess of Vitamin A in retinoid form is harmful and can even be fatal and excessive intake of Vitamin A is believed to be linked to osteoporosis.

Once absorbed by the body, Vitamin A is stored in the liver in ester form until retinol is needed in other parts of the body. It is then released into the blood stream and carried elsewhere to the body. The recommended daily amount (RDA) for Vitamin A is approximately 900 micrograms per day, depending on age, gender, and health. It is recommended that the average adult should not consume more than 1500 micrograms (5000 IU) per day.

While Vitamin A is an essential nutritional requirement, the uses of retinol are also widespread in the cosmetic and clinical industries. Retinol is used in topical applications in the form of gels and creams and is available in both over-the-counter products as well as by prescription. Tretinoin is a clinical retinoic acid that is used by dermatologist to treat patients with acne. Many cosmetics, including skin creams, contain retinol as well. Derivatives of Vitamin A absorbed through the skin are believed to increase skin cell production and collagen, which can help smooth damaged or wrinkled skin over time.