Vitamin C. Molecular graphic of vitamin C (C6H8O6, also called ascorbic acid). Coloured spheres represent atoms: carbon (green), oxygen (red) and hydrogen (white). Solid lines represent bonds. Vitamin C is a water-soluble vitamin that plays an essential role in the activity of many enzymes in the human body. It is necessary for the growth and maintenance of healthy bones, gums, teeth, ligaments and blood vessels. Dietary sources include citrus fruits and green vegetables. Deficiency leads to scurvy, with symptoms such as swollen, bleeding gums and anaemia.