Any girlies who take vitamins throw up after?

I’ve always had a VERY bad immune system my whole life but I’ve always been very healthy so i never understood it. A couple years ago i was told i had very low iron and i needed to start taking iron pills. i started taking iron pills but every-time i took them i would throw up maybe an hour later. I stopped taking them because of it, fast forward i 2021 i got covid and it was pretty bad, after covid the tastes and smells of things were awful. I later learned i had something called parosmia i hated it and my mom ended up finding a vitamin that would bring my senses back, so i started taking them and every-time i would throw up because of them. So once again i stopped taking them. Recently i got diagnosed with mono and it absolutely sucks the worst sickness I’ve ever had. I’ve struggled to sleep which is weird because people say that’s all they do with mono but i’ve been so severely sick i just can’t sleep. I talked to my mom and had told her i think i need to start taking vitamins everyday and she ofc agreed because my immune system is horrible so everyday i’ve been taking these supplements before bed and then I’m up all night sick and throwing up can someone please explain why my body does this?