I take a few different things for various issues, but a lot of them overlap as TTC supplements. The main ones are folate (not synthetic folic acid, as many people are unable to absorb synthetic folic acid), activated b-12, vitamin e, vitamin c, and iron. The last one is taken because I'm anemic, but it is related because untreated anemia can impact conception efforts.
I had a very early miscarriage a couple of months ago, and I'm trying to be extra careful about what I do and don't take since then.