If your prenatals are not liquid, then you should not take them while on the MC. You don't want to put any solids into your system that your body will have to digest. It will take away from the purpose of the cleanse.

I am a "by the book" MC'er, and I don't use anything that is not mentioned in the book while I am on my fast. But I can see how some people may have circumstances where additional supplementation may be necessary. If I were in your situation, I would look at taking a liquid vitamin while on the MC.

Tiffany