Vitamin C is a water-soluble nutrient essential for life, used by the human body for many purposes. To the best of scientific knowledge, all animals and plants synthesize their own vitamin C, except for a small number of animals, including guinea pigs, humans, apes, the red-vented bulbul, a fruit-eating bat and a species of trout, that are not able to. This, along with the related fact that man possesses three of the four enzymes that animals employ to manufacture the substance in relatively large amounts, has led researchers such as Irwin Stone and Linus Pauling to hypothesize that man once manufactured this substance in the body millions of years ago in quantities roughly estimated at 3-4,000 mg daily, but later lost the ability to do this through evolution. If true, this would of course mean that vitamin C was misnamed as a vitamin and is in fact a vital macronutrient like fat or carbohydrate.
Vitamin C was first isolated in 1928, and in 1932 it was proved to be the agent which prevents scurvy. Albert Szent-Györgyi was awarded the Nobel Prize for this feat.
Vitamin C is a weak acid, called ascorbic acid or ascorbate (an L-enantiomer of ascorbic acid; an l-enantiomer is simply one of two mirror image forms of the same chemical molecular structure, see optical isomers). The active part of the substance is the ascorbate ion, which can express itself as either an acid or a salt of ascorbate that is neutral or slightly basic. Commercial vitamin C is often a mix of ascorbic acid, sodium ascorbate and/or other ascorbates.
