The national recommendations are changing about calcium and vitamin-D intake for children. Intake of these are not just important for strong bones for growing children but to prevent osteoporosis in elderly adults. Osteoporosis is a disease of the bones that causes the bones to be more fragile and to break easily. A healthy intake of calcium and vitamin-D in childhood helps build healthy bones ("bone mass"). Childhood and the teenage years are the best years to build these strong bones: by 18 years of age, about 90% of bone mass has already been made.
Daily Calcium Needs:
1-3 Years of Age: 700 milligrams
4-8 Years of Age: 1000 milligrams
9-18 Years of Age: 1300 milligrams
Note that there is about 300-400 milligrams of calcium in a serving of dairy products. A serving of dairy is considered to be 8 ounces of milk, 8 ounces of yogurt, and 1.5 ounces of cheese. Other foods rich in calcium: salmon, tofu, orange juice supplemented with calcium, broccoli, spinach, baked or white beans, sesame seeds, peas, almonds, and Brussel sprouts. See a link here for more info on good sources of calcium. So if your child only gets calcium from milk, a 1-3 year old needs 16 ounces a day, a 4-8 year old needs 24 ounces per day, and a 9-18 year old needs 3-4 servings per day. Note that you would need 4-6 cheese slices or sticks to get 700 milligrams a day (that is quite a bit!). Most cheese sticks are 1 ounces of cheese and the average slice of cheese has 0.6 ounces.
Daily vitamin-D Needs:
Birth-1st Birthday: 400 IU
1-18 Years of Age: 600 IU
Note that infants who are exclusively breast-fed or who take less than 16 ounces of formula per day should take a daily dose of vitamin-D. Formula fed infants do not need a supplement as the formula has vitamin-D. Baby ddrops(r) have 400 IU of vitamin-D in one drop. See more information here. Enfamil D-Vi-Sol(r) has 400 IU in 1 milliliter with more information here. There are other over the counter options.
For older children who are allergic to dairy, struggle to get it in, or who otherwise need a supplement, it is the Viactiv(r) chews that we recommend. These over the counter chews have 500 IU of vitamin-D and 500mg of calcium. Therefore the dose would be 1-2 chewables per day, depending on age and other sources of vitamin-D or calcium.