Retinol is a form of vitamin A - a group of organic nutritional compounds that are naturally found in a variety of foods and acts as an aid in maintaining the functioning of the immune system, skin health and preserving good vision. It is used in medications and dietary supplements that treat or help prevent vitamin A deficiency. Although it is sometimes available as a standalone medication or supplement, retinol is more commonly found in pharmaceutical formulations along with other nutritional compounds. In use for over 70 years, the vitamin has since become included in the World Health Organization’s list of Essential Medicines that contains the most important medications recommended for a basic health system. Research by the WHO estimates that throughout the past couple of decades, the availability of vitamin A supplementation has successfully aided in averting over 1.25 million deaths due to vitamin A deficiency in 40 countries. Prices of dietary supplement formulations with retinol vary widely depending on the concentration of retinol in the formulation, other ingredients that are contained in the formulation as well as supplier and manufacturer pricing.