Ascorbic acid (vitamin C) is used as a dietary supplement when the amount of ascorbic acid in the diet is not enough. People most at risk for ascorbic acid deficiency are those with a limited variety of food in their diet, or who have intestinal malabsorption problems from cancer or kidney disease. Ascorbic acid is also used to prevent and treat scurvy (a disease that causes fatigue, gum swelling, joint pain, and poor wound healing from a lack of vitamin C in the body).
Ascorbic acid is in a class of medications called antioxidants. It is needed by the body to help wounds heal, to enhance the absorption of iron from plant foods, and to support the immune system. It works as an antioxidant to protect your cells against free radicals, which may play a role in heart disease, cancer and other diseases.