User:Mr. Ibrahem/Retinol

Retinol, also known as vitamin A1, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat and prevent vitamin A deficiency, especially that which results in xerophthalmia. In regions where deficiency is common, a single large dose is recommended to those at high risk a couple of times a year. It is also used to reduce the risk of complications in those who have measles. It is used by mouth or injection into a muscle.

Retinol at normal doses is well tolerated. High doses may result in an enlarged liver, dry skin, or hypervitaminosis A. High doses during pregnancy may result in harm to the baby. Retinol is in the vitamin A family. It is converted in the body to retinal and retinoic acid through which it acts. Dietary sources include fish, dairy products, and meat.

Retinol was discovered in 1909, isolated in 1931, and first made in 1947. It is on the World Health Organization's List of Essential Medicines. Retinol is available as a generic medication and over the counter. The wholesale cost in the developing world is about US$0.02–0.30 per 50,000 units. In the United States it is not very expensive.