What vitamins can I take for pregnancy if I don't want to take prenatal vitamins?

You need folate (folic acid) The most important vitamin during pregnancy is folic acid. Speak with your obstetrician to make sure you are getting what you need. Most of what else you need you can get from whole foods like fruits, vegetables, nuts, beans and whole grains and it will probably be better for the baby.
Folate/iron/calcium! If you can tolerate Folic Acid (1-5 mg daily) iron and calcium supplements, you do not need to take the full prenatal vitamins (can cause increased nausea in some expectant mothers). Talk to your obstetrician or midwife about this as well.