Many parents ask why they can't just feed their baby regular cow's milk. The answer is simple: Infants cannot digest cow's milk as completely or easily as they digest formula.
Also, cow's milk contains high concentrations of protein and minerals, which can stress a newborn's immature kidneys and cause severe illness at times of heat stress, fever, or diarrhea. In addition, cow's milk lacks the proper amounts of iron, vitamin C, and other nutrients that infants need. It may even cause iron-deficiency anemia in some babies, since cow's milk protein can irritate the lining of the stomach and intestine, leading to loss of blood in the stools. Cow's milk also does not contain the healthiest types of fat for growing babies. For these reasons, your baby should not receive any cow's milk (or other non-human milk or milk substitute) for the first twelve months after birth.
Once your baby turns a year old
Once your baby is past one year old, you may give them whole cow's milk or reduced-fat (2%) milk, provided they have a balanced diet of solid foods (cereals, vegetables, fruits, and meats). But limit his intake of milk to 2 cups (about 16 ounces) per day or less. More than 24 ounces a day has been associated with iron deficiency if todders arent' getting enough other healthy iron-rich foods. If your baby is not yet eating a broad range of solid foods, talk to your pediatrician about the best nutrition for them.
At this age, children still need a higher fat content, which is why whole vitamin D-fortified milk is recommended for most infants after one year of age. If your child is or is at risk for having overweight, or if there is a family history of obesity, high blood pressure, or heart disease, your pediatrician may recommend 2% (reduced-fat) milk.
Age 2 and up
Do not give your baby 1% (low-fat) or nonfat (skimmed) milk before their second birthday, as it does not contain enough fat for brain development. After two years of age, you should discuss your child's nutritional needs, including choice of milk products, with your pediatrician.