Last night on the Discovery channel's Daily Planet(in Canada) a short segment was shown demonstrating Vitamin C's effect on Iodine.
I didn't catch the beginning, but from what I gathered, Iodine is an oxidizer?) and Vitamin C an anti-oxidant, and to demonstrate this point the scientist painted a small patch of Iodine on his palm and then rubbed it with a wetted Vit. C tablet.
The Iodine stain slowly disappeared.
Lends credence to what someone said (V.?)earlier about taking the Vit. C an hour away from the Iodine.