Obimin

I am now in 20weeks. So far hb ok. Bila tanya nurse bila boleh mkn obimin sebab last pregnancy,masuk bulan ketiga dah consume obimin. Tp die xsuggest consume obimin since kandungan zat besi dlm bdn ok n hb pon ok. So kena consume folic asid je. Any doctor yg boleh confirm this fact? Checkup dekat KK je.. what if kalau i amek je obimin tu? Any effect ke kalau terlebih zat besi?