Hello, and I hope I can help you today. Most women experience constipation from both the hormones of pregnancy and from taking vitamins, because they also tend to cause constipation. But everyone reacts to different medications differently, and the particular brand of vitamin you are using may be hard to digest. I suggest you just try a different brand of prenatal vitamin. There is nothing to worry about if you have looser stools as long as they do not contain blood or are not completely watery diarrhea, or causing severe abdominal pain. I hope I was able to answer your question and that this information was reassuring. Best wishes for the rest of the pregnancy, Dr. Brown