I take lots of vits and sups and never had a problem.
I know some people take vit b6 to increase their LP if short. Maybe taking too much with a normal LP can cause a problem. Not sure, as I take a bcomplex and am fine.
EPO should not be taken after O.
Vitex and such can cause issues for many women. I would not take Vitex, soy etc unless under a dr's suppervision and recomendation. They may help some people but willy nilly taking them has resulted in many a messed up cycle.