The Real Reason Newborn Babies Shouldn't Drink Cow's Milk

Cow's milk should not be given to babies for the first 12 months of life, according to the American Academy of Pediatrics (AAP). Cow's milk contains high levels of protein, sodium, and potassium, which a newborn baby's immature kidneys cannot handle. This can lead to severe illness, including heat stress, fever, and diarrhea. 

Cow's milk also doesn't contain sufficient amounts of essential vitamins and nutrients, including vitamins C and E, iron, and fatty acids (via MedlinePlus). In fact, it can even lead to iron-deficiency anemia, since cow's milk can irritate the stomach lining and intestine, causing blood loss in stools. Additionally, newborns cannot digest cow's milk easily or completely, and the unhealthy fat it contains isn't the best for a baby's growing body.

The AAP recommends babies receive breast milk as the sole source of nutrition for the first six months of life. If breastfeeding is not possible, infant formulas are a healthy alternative. At six months, water and solid foods may be introduced into a baby's diet.

When is it safe to transition to cow's milk?

Once infants have passed their first birthday, it is safe to give them whole or 2 percent cow's milk, according to the AAP. This should only be done if your baby has a balanced diet of solid foods, such as fruits, vegetables, and cereals. Cow's milk should be limited to about 1 quart per day, as any more may decrease your baby's appetite for other foods. Talk to your pediatrician about introducing cow's milk if your baby is not eating a broad range of solid foods.

Infants should not be given 1 percent or skimmed (nonfat) milk before they turn 2, as these contain too high a concentration of protein and minerals for their system. A pediatrician should be consulted before introducing low-fat or nonfat milk products after the age of 2.

The AAP also recommends against giving infants 12 months and younger juice of any kind. While eating whole fruit is preferred, when that is not an option, small amounts of 100 percent juice may be given to children ages 2 to 5. Flavored milk, like chocolate or strawberry milk, should not be given to infants younger than 2 and should also be avoided in all children under the age of 5 to minimize added sugars in the diet. Plant-based milks (other than soy milk) are not recommended for children to drink in place of dairy milk. Toddler milk, sugary drinks, and caffeinated beverages should not be given to infants or children.