Vitamin C (ascorbic acid) has numerous biological functions. Vitamin C helps towards collagen formation for many body tissues including skin, gums, teeth and cartilage found in joints. It enhances the absorption of iron in the body, is involved in energy metabolism, and contributes to the reduction of tiredness and fatigue. Vitamin C is the required coenzyme for two groups of enzymes that catalyze the crosslinking of collagen fibers – lysyl hydroxylases and prolyl hydroxylases. Vitamin C is essential for normal wound healing and capillary health. It also participates in the biosynthesis of carnitine, serotonin, and certain other neurotransmitters, including norepinephrine. Vitamin C is a water-soluble, chain-breaking antioxidant that reacts directly with superoxide, hydroxyl radicals, and singlet oxygen. Vitamin C interacts with glutathione and alpha-lipoic acid, and regenerates Vitamin E.
Bioflavonoids (also called flavonoids) are a class of phytochemicals that are potent antioxidants, which scavenge many potentially damaging free radicals. Another aspect of the antioxidant properties of bioflavonoids is their synergy with Vitamin C. The bitter tasting flavanones hesperidin and naringin, from the white albedo layer of citrus peels, have been shown to extend the nutritional functions of Vitamin C. Bioflavonoids are also capable of binding to metal ions, which prevents these metals from acting as catalysts in the body to enhance free radical production.