Ascorbic acid is commonly known as vitamin C, and is an essential nutrient. This means that it cannot be produced by the body, and must therefore be obtained from diet or supplements. Vitamin C has many important functions; however, it cannot be stored in the body for a long time. Although there is a pool of vitamin C in the body, there is a constant turnover of this vitamin, and any excess that is consumed is excreted. A daily, continuous intake of vitamin C is required, because it is a water-soluble vitamin.