Vitamin C imaged with polarised light. Vitamin C (ascorbic acid) is an important vitamin, essential for collagen formation and wound healing, it also facilitates to absorption of iron. A good source of vitamin C is found in a variety of fruit and vegetables, notably citrus friuts, kiwi and broccoli. It is a water soluble vitamin so is excreted by the body and, therefore, needs to be ingested regularly. A lack of vitamin C causes scurvy.