Cow's Milk: What parents should know
Currently, The Canadian Pediatric Society recommends breast milk or iron-fortified formula for the first 9-12 months.(The American Academy of Pediatrics recommends that babies not be given whole cow's milk for the first 12 months of life). There are many reasons for this, but the most important is related to the iron needs of a child. Iron is an essential part of red blood cells. When the body does not have enough iron to make red blood cells "anemia" (or decreased level of red blood cells) will develop. Normally, babies are born with enough iron in their body for the first few months of life. However by 3-4 months, extra iron is needed. This extra iron should come from the child's diet and this is why iron-fortified formula is recommended for infants who are not breast-fed.
For a variety of reasons, whole cow's milk is considered to be a very poor source of iron. In addition, the protein in cow's milk is not easy to digest by babies. By far, the best source of iron, and other nutrients for a baby is breast milk. For this reason breastfeeding should continue for as long as possible. However when breastfeeding is not an option, baby should be drinking iron-fortified formula which contains enough iron and all other essential vitamins and nutrients to support normal growth and development. In addition, infant formulas contain modified cow's milk protein that a baby can more easily digest.
Prior to the current recommendation, babies were switched to whole cow's milk at 6 months of age, or even earlier. The reason that the period on iron-fortified formula or breast milk has been extended is that studies have shown a surprising amount of iron deficiency anemia in children less than a year of age. We also now recognize that iron deficiency anemia in the first year has been linked to developmental delays, that unfortunately, in some cases are not reversed by adding iron to the diet later. Therefore prevention of iron deficiency anemia is our goal.
Whole cow's milk is not suitable for most of the first year of life. While the exact timing of the switch should be discussed with your doctor, whole cow's milk should only be introduced when baby is eating adequate amount of solid foods containing iron and vitamin C, preferably between 9 to 12 months of age. On a final note, remember, when the switch is made, it should be to be to whole cow's milk only, as skim or 2% milk are not recommended for children less than 2 years old.