Cow’s milk is the single most complete food on Earth — no other food has as many nutrients. So, it is understandable if a mother might be eager to start her baby on cow’s milk as soon as possible.
However, doctors advise against giving cow’s milk to an infant before he or she has turned one year of age. There are several reasons for this.
It is cow’s milk’s very nutritiousness — the sugars, fats, proteins and minerals in it (calcium, phosphorus and potassium, to name the three most prominent) — that make it difficult for young babies to digest, since their digestive systems are still maturing.