Why wait until 12 months?
During the first year, your baby's main milk is breast milk or infant formula. Cow's milk does not have the right balance of nutrients a baby this age needs. For example, it is low in iron and vitamin C. Its high protein and mineral content can strain immature kidneys. In some babies it can also cause bleeding in the gut that you cannot see, and iron deficiency anemia.
Small amounts in cooking
The UK's NHS says cow's milk can be used in cooking or mixed into food from around 6 months. This is different from giving milk as a drink. US sources advise no cow's milk before 12 months. These sources do not address cooking separately. If you are unsure, ask your baby's doctor.
How much milk after 12 months?
Once your baby turns 1, you can offer pasteurized cow's milk as a main drink. The American Academy of Pediatrics (AAP) recommends whole milk for children aged 12 to 24 months. The AAP suggests about 2 cups, or roughly 470 ml, a day at this age. The AAP also notes that more than 710 ml a day has been linked to iron deficiency. A child who drinks a lot of milk may not be hungry for other foods.
Whole or semi-skimmed?
The AAP advises against skim or 1 percent milk before age 2. These milks do not have enough fat for brain development. The NHS accepts whole or semi-skimmed milk as a main drink from age 1. According to the NHS, skimmed and 1 percent milk should not be a main drink before age 5. Do not give your child raw, unpasteurized milk.
Plant drinks
Plant drinks should not replace milk before 12 months. If you choose one after age 1, pick an unsweetened drink with added calcium and vitamin D. According to the AAP, soy drink is the plant option that matches cow's milk in nutrition. The NHS advises against rice drinks for children under 5 because of their arsenic content. If your child has a milk allergy or intolerance, choose the right option with their doctor.
If your baby is not yet eating a range of solid foods at age 1, talk to their doctor about their diet. Your child's doctor can also give the best advice on how much milk and which type to offer.