I take a full prenatal vitamin to cover my nutritional gaps. Vitamin d and folic acid are super important, but making sure you get enough calcium and a few other vital nutrients is important as well. Sometimes a growing fetus can sap your calcium from your bones and teeth if you do not have enough stored up/getting enough daily. Prenatal DHA is another one you might want, especially if you don't eat enough fish. It is important for brain development. You can find prenatals and the prenatal dha combined or separate. Make sure you clear whatever supplement with your doctor of course.
I take https://www.amazon.com/Simply-One-Prenatal-90-Tab/dp/B000Z94YQW/ref=sr_1_1?ie=UTF8&qid=1435390706&sr=8-1&keywords=simply+one+prenatal it is simply one prenatal