Help! I can't keep my prenatals down!

This is my first pregnancy and I'm 8 weeks and have been experiencing A LOT of naseau and vomiting, especially after taking my prenatal vitamins. I've tried taking them in the morning, in the afternoon with lunch, at night after dinner, right before bed... It doesn't matter when I take them, I always throw them up. I'm afraid that my baby isn't getting the nutrients he /she needs. Any advice on what else I could try would be greatly appreciated!