Sky Premium Life Vitamin C 500mg 60tabs (Dietary Supplement to Boost Immune System) Vitamin C is an essential vitamin that cannot be synthesized by the human body. Known as ascorbic acid, it is a water-soluble nutrient and a powerful antioxidant that protects the body from free radicals, which play a key role in the aging process. Vitamin C's role as an antioxidant also helps repair tissue and reduce damage from inflammation and oxidation. It is necessary for the proper development and functioning of many parts of the body. It also plays an important role in maintaining proper immune function.