Regular multivitamins and prenatal vitamins are safe to take during pregnancy and can be helpful. Women who are pregnant or trying to get pregnant should take a daily multivitamin or prenatal vitamin that contains at least 400 micrograms (µg) of folic acid. It is best to start taking these vitamins before you become pregnant or if you could become pregnant. Folic acid reduces the chance of a baby having a neural tube defect, like spina bifida, where the spine or brain does not form the right way. See our information on Folic Acid. Iron can help prevent a low blood count (anemia). It's important to take the vitamin dose prescribed by your doctor. Too many vitamins can harm your baby. For example, very high levels of vitamin A have been linked with severe birth defects.