Is there any mummies who have stop their obimin at 3rd trimester?

Hi mummies, I am coming to third trimester and have stop taking my obimin for quite sometime because whenever I took it, it triggers my nausea and I always vomited due to this vitamin! Thus I’ve stopped taking it! But after I’ve stopped taking it, no nausea and puking! So far when I go for scanning, everything’s alright though. And I wonder if those people or doctors said it’s important to take the vitamins for babies development and brains, ever thought of those old folks people like our grandmothers who don’t take such vitamins when preggy? Or those poorest people who can’t afford babies check up during the olden days and their kids turn out well without those vitamins?