Ascorbic acid is a colorless, odorless, crystalline, water-soluble solid with an acidic taste. It is an organic acid, more precisely a vinyloge carboxylic acid; its salts are called ascorbates. Ascorbic acid is available in four different stereoisomeric forms, but only L-(+)-ascorbic acid has biological activity. An important property in humans and some other species is its physiological effect as a vitamin. A deficiency can manifest itself as scurvy in humans. The name is therefore derived from the Latin name of the disease, scorbutus, the 'antiskorbutic' acid. Since ascorbic acid is easily oxidizable, it acts as a reductone and is used as an antioxidant.