Prenatal vitamins? Important?

Sarah
On a scale of one to life and death how important are prenatal vitamins? I was always good about taking them in my past pregnancies but this is my fourth and not only am I too scatterbrained to remember them but they also make me sick if I don't take them under the right conditions. Opinions? I have horse pills for a prescription and I know there are gummies but I have to pay for those out of pocket