Vitamin C, also known as ascorbic acid, is a water-soluble vitamin that contributes to some important functions in the body.  Vitamin C is required for collagen formation and tissue repair and formation of certain neurotransmitters. One of the best-established functions of vitamin C is in the regulation of neurotransmitter formation, including dopamine, norepinephrine, and epinephrine, which are essential for nervous system function. Vitamin C is also a highly effective antioxidant and can effectively help protect important cells from free radical damage. It is likely this antioxidant role that has vitamin C supplementation promoted for helping with several diseases, but these have not been verified by research.

Humans do not make or store Vitamin C, so it is important to replenish daily. Our bodies need between 500 and 2000 milligrams of Vitamin C a day to carry out its important functions. While Vitamin C can be found in many food sources, it can be easily destroyed by heat and light, or dissolve into cooking liquids since it is water-soluble. If your main source of Vitamin C is coming from your diet, it is best to eat foods raw, or prepare them with the least amount of liquid possible. Supplementing with oral or injectable Vitamin C is important to ensure you are absorbing enough. Although deficiency in Vitamin C is rare in developed countries, when it does occur it can present with symptoms such as decreased energy, muscle and joint pain, bruising and weight loss.