questions?

I haven't been actively ttc but I have been off bc for about 3 years now with no luck of it just so happening.. no protection is involved. I've been with my bf now for going on 4 years! I was wondering if taking about have a pill of prenatal vitamins might give me a boost in the vitamins I need to carry in case I don't get enough of what I need or is this a bad idea? I would really appreciate any input :) thankyou ladies!