Vitamin C or L ascorbic acid or L ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress. It is also a cofactor in at least eight enzymatic reactions including several collagen synthesis reactions that cause the most severe symptoms of scurvy when they are dysfunctional. In animals these reactions are especially important in wound healing and in preventing bleeding from capillaries. Ascorbate an ion of ascorbic acid is required for a range of essential metabolic reactions in all animals and plants. It is made internally by almost all organisms although notable mammalian group exceptions are most or all of the order chiroptera bats, guinea pigs, capybaras, and one of the two major primate suborders, the Anthropoidea Haplorrhini tarsiers, monkeys and apes, including human beings. Ascorbic acid is also not synthesized by some species of birds and fish. All species that do not synthesize ascorbate require it in the diet. Deficiency in this vitamin causes the disease scurvy in humans. It is also widely used as a food additive.