And you your money. My kid was sleeping great for a newborn. 2-3 sometimes 4 hours on a good feed. Well since he is breast fed, the recommendation was to start vitamin D. Ok, no biggie. Well we used Enfamil drops once a day. It has been, NO JOKE the worst! It made my baby SO gassy, so uncomfortable, so irritable. Poor kid was writhing in pain, crying, and up every 45 min - 1 hr. Stopped the drops and within a day, he was soooo much better. Did some research, and seems a lot of parents had this side effect as well. We changed to Carlson’s 1 drop a day and what a dramatic change. So just figured I would share this with you guys, in hopes of saving your baby some pain, and mommy some sanity!!