I didn't take any supplements and even stopped taking my usual krill oil and just got through the six lots of chemo as best as I could. Lots of vegetable juices. As soon as it was all over I talked to the oncologist and she is a firm believer in a good balanced diet and that we don't need all the supplements except I do take calcium and vit d now to help with the aromasin drug I have to take.
I'd say go with your gut feeling but I just didn't want to take any more pills than necessary and there were quite a few during chemo. My chemo went from jan to may and I can't tell you how glad I am that it's over but each time I felt it was about 25 percent better.
Wishing you all the best. Be kind to yourself!