Since 1947 Natural Bioflavonoid Non-GMO Gluten, Wheat & Dairy Free Suitable for Vegetarians Kosher Parve Dietary Supplement Rutin is an important, non-citrus, antioxidant, bioflavonoid. Flavonoids are a group of water soluble plant pigments found naturally in many foods. They help your body to absorb and utilize Vitamin C. The natural source Rutin in this formulation helps the body to fight free radicals which damage cells through oxidation.