I was advised not to take extra vitamins during treatment. I was told I could take a multivitamin if I wanted (and I had no choice once I started using jevity for my nutrition) but that higher doses of antioxidants were not advisable. Once treatment was over, it didn't matter to my doctor. But there have been sme scary studies abiout the effects of vit. E and recurrences. Rhe fact is, no one really knows how antioxidants affect cancer tumors or cells. The only vit. that has good solid research showing it to be HELPFUl is vit. D in preventing breast cancer. I take extra Vit. C and D now and that's it.