We used to think of cow's milk as a nearly perfect food. However, over the past several years, researchers have found new information that has caused many of us to change our opinion. This has provoked a lot of understandable controversy, but I have come to believe that cow's milk is not necessary for children. First, it turns out that the fat in cow's milk is not the kind of fat ("essential fatty acids") needed for brain development. Instead, milk fat is too rich in the saturated fats that promote artery blockages. Also, cow's milk can make it harder for a child to stay in iron balance. Milk is extremely low in iron and slows down iron absorption. It can also cause subtle blood loss in the digestive tract that causes the child to lose iron. … Some children have sensitivities to milk proteins, which show up as ear problems, respiratory problems, or skin conditions. Milk also has traces of antibiotics, estrogens, and other things a child does not need. There is, of course, nothing wrong with human breast milk — it is perfect for infants. For older children, there are many good soy and rice milk products and even nondairy "ice creams" that are well worth trying. If you are using cow's milk in your family, I would encourage you to give these alternatives a try.
Benjamin Spock