Quote Originally Posted by doc
Science 2001 Jun 15;292(5524):2083-6 (ISSN: 0036-8075)
Lee SH; Oe T; Blair IA
Center for Cancer Pharmacology, University of Pennsylvania, 1254 BRB II/III, 421 Curie Boulevard, Philadelphia, PA 19104-6160, USA.
As far as I can tell, this study compares the damage caused by vitamin C in the *absence* of transition metals (like Iron) to the damage done *by* such metals. The conclusion? They're quite similar, and C might be a smidge more effective at promoting the reaction that results in the potential damage. But the thing of it is, C is so good at scavenging reactive oxygen, that it's pretty much used up by the copious free radicals in the body, which is why the transition metals had to be chelated off for the experiment to work. (The presence of transition metal ions in vit C solutions causes a relatively rapid loss in absorbance at 265 nm resulting from oxidation of vit C to its dehydro form. CuII is approximately 80 times more effective than FeIII at oxidizing vit C (20).)

The conclusion was that more studies need to be done, that maybe this is why C isn't therapeutic against cancer, and that people who are at risk for "lipid hydroperoxide-mediated DNA damage" might want to keep tabs on their vitamin C ingestion.

'Least that's how I read it.