Vitamin C 500 Buffered by Schiff/Bio Foods. Vitamin C, also known as ascorbic acid, is a water-soluble vitamin needed by the body for many vital metabolic reactions. Vitamin C is needed as a coenzyme for many metabolic pathways. Vitamin C is a powerful antioxidant, with important roles in connective tissue, bone and skin health, immune function, and cardiovascular health. It is also necessary to convert folic acid into its active form, and Enhances the body absorb iron. Good food sources of vitamin C include all citrus fruits (oranges, grapefruit, lemons), strawberries, tomatoes, broccoli, Brussels sprouts, peppers, potatoes and cantaloupe. This formula combines vitamin C with rose hips (a natural form of bioflavonoids) and is buffered in case the acidic nature of Vitamin C irritates your stomach.