Some kids can be very picky eaters and may not get enough vitamins and minerals, including iron. So if your child does not get all his nutritional needs from his diet, then a multivitamin with iron could be useful. I gave my daughter a multivitamin without iron for some time without realizing it and she became anemic because she refuses to eat any food that contains iron. My daughter also takes a calcium, magnesium and zinc mineral supplement at night, which helps her calm down to go to sleep. I give her a probiotic every day because she takes antibiotics every day and I think she had some bad bacteria or yeast in her intestines that were causing problems. We tried an Omega 3 fatty acid supplement, but I did not see much difference with her speech or anything else. I think our kids are all different, and what works well for one will not necessarily work for all.