Vitamin C contributes to inflammation via radical generating mechanisms: a cautionary note.

Reactive oxygen and nitrogen species (RONS) have been ascribed an important role in oxidative stress contributing to the progression of inflammatory diseases such as Crohn's disease and rheumatoid arthritis. Redox-active metal ions such as Fe(II) and Cu(I) further activate RONS and thus perpetuate their damaging effects. High intake of ascorbic acid exerts a pro-oxidant effect by its interaction with metal ions via a number of established RONS generating systems. Caution should be exerted regarding surplus ascorbic acid intake for patients with chronic inflammatory diseases.