I think they're fine. Most things I've read suggest those vitamins be taken in addition to chelators not instead of them. That likely means they don't have a strong chelating effect by themselves. Though there may be some methods I haven't seen...
Listen to your body. Your body will tell you if they are chelating or not. Your body will also tell you if it can handle the vitamins or not. If you're not sure, stop taking them and see how you feel in a few days.