Bioflavonoids are plant compounds that give plants their colour and are found mostly in fruits, vegetables and certain tree barks. Previously known collectively as vitamin P, the bioflavonoids include a number of vitamin C-like components that work together - citrin, rutin, flavonols, catechin, proanthocyanidins, polyphenols and quercetin are a few of the more common ones. As a class, bioflavonoids are powerful antioxidants which help protect our bodies from harmful free radicals. They also have antiviral, anticancer and antiallergenic actions. The main use of the bioflavonoids would be to provide synergy in the utilisation of vitamin C - they therefore contribute to many vitamin C applications, for example, the treatment of colds and flu's.