Vitamin C. Polarised light micrograph of crystals of vitamin C, or ascorbic acid. It is a water soluble vitamin and plays an essential role in the activity of many enzymes in the human body. It is important for the growth and maintenance of healthy bones, gums, teeth, ligaments and blood vessels. It is involved in the production of neurotransmitters and in the stimulation of the immune system against infections. The main dietary sources of vitamin C are citrus fruits and green vegetables. The recommended daily intake for an adult is 30 milligrams. Severe deficiency leads to scurvy, characterised by swollen bleeding gums and anaemia. Magnification: x15 at 6x7cm size. magnification:x25 at 4x5 inch size.