I've read that the consumption of iron and vitamin C together is associated with stomach cancer.
If you have low iron (e.g. low ferritin), it can be raised by consuming a lot of antioxidants instead of iron itself. Iron is a pro-oxidant, so hopefully you aren't feeling worse after consuming iron because of this. Copper is in the same category, and problematic with impaired bile production. Chromium at 600-1000mcg/day divided into 3 or 4 doses is fairly safe.