For many years it was easy: The American Academy of Pediatrics recommended whole milk from 1 year to 2 years of age, then 2% until 4 years. At 4 years it was recommended to switch to skim milk. If kids couldn't tolerate cow's milk they were given soy.
Then came questions about the estrogen like effects of soy and the problem that soy allergy is common in milk allergic kids.
The obesity rates climbing in kids has put into question whether whole milk is needed until 2 years and if lower fat milks should be given at younger ages. The answer to this is probably not routinely, but toddlers who are overweight can benefit from a lower fat milk.
Grocery store shelves now offer not only whole, 2%, 1%, and skim cow milks (regular, hormone free and organic of each of these!) and soy milk, but they also sell lactose free milk (in several fat concentrations), rice milk, almond milk, coconut milk, and goat milk.
How do you make the right choice for your child? Below is a nice chart from MyHealthNewsDaily.com comparing calories, fat, protein, and calcium contents of various milks. Taste is a very important consideration for the picky child. If they don't like the taste, they will not drink it. Even the textures of the milks can vary quite a bit and might require acclimation. Food allergies and intolerances drive many of the choices. Note: none of these are appropriate for infants under one year. Breast milk or formula are the only healthy options for infants due to other nutrients needed in an infant's diet!
Historically it has been felt that toddlers need more calories from milk, and should not regularly drink a low fat/low calorie milk. Because of the rising obesity rates (even among toddlers and preschoolers) this recommendation is changing and kids can drink lower calorie products if their caloric intake from foods is sufficient. Beware of high calories in milks like coconut milk, goat milk, rice, or soy milk. They have nearly as many calories (or more!) than whole fat cow's milk.
One cup of coconut milk has over 50 grams of fat and over 460 calories! A special treat: yes. A routine daily drink: no!
(For comparison, a BK vanilla milkshake has 412 calories and 23 grams of fat in 227 grams (just 1/2 oz shy of a full cup).
Calcium levels vary widely in various milks and should be taken into consideration when choosing a milk for your child. Other foods, such as calcium fortified orange juice, yogurt, tofu, leafy greens, cheese, and fortified cereals, can (and should) incorporate calcium into the diet.
Vitamin D is very difficult to get through diet alone and it is recommended that everyone take a Vitamin D supplement. For more information, click here.
There is no consensus that organic milk offers any health benefit. Due to it's high cost, it is prohibitive for many families to buy organic. Hormone free milk is available for a mid-range cost without the potential (yet unproven) risks of hormones given to cows. There isn't any nutritional benefit of the hormone free milk or organic milk compared to conventional milk, but if you are concerned about hormone exposure from milk, hormone free is less expensive than organic.
Lactose free milk: 160 calories, total fat 9g, protein 8 g, calcium 30%
Lactose free reduced fat milk: 130 calories, total fat 5g, protein 8 g, calcium 30%
Lactose free fat free milk: 80 calories, total fat 0g, protein 8g, calcium 30%
(Lactose milk nutrition facts based on one cup, from www.fatsecret.com)