Good vitamin D supplements to take during pregnancy?

Yesterday I had my first OB appt (12 weeks) with my CNM. As part of my appointment they took my labs. I got my results back and notice that my vitamin D levels are a little below the normal range; my level is 24 ng/ml and the normal range is 30-80 ng/ml. Accordingly, my over the counter prenatal isn’t providing me with enough vitamin D and living in a state with a cold climate and very little sunshine currently, I have very little opportunity of getting it naturally from the sun until summer. I want to go purchase an over the counter vitamin D supplement to take in addition to my prenatal but not quite sure which one to buy.

Any suggestions on over the counter vitamin D supplements that are safe to take during pregnancy (I.e brands)?