Vitamin C, also called ascorbic acid, is a water soluble vitamin that we get mostly from fruit and vegetables, especially citrus fruit. It is among the body's most important antioxidants, fighting oxidative stress. It is important for immunity, connective tissue such as blood vessels, bones, cartilage, gums, skin and teeth. It helps iron absorption. It is involved in energy metabolism, contributes to a healthy nervous system and psychological function, and reduces tiredness and fatigue.