Soy-based beverages are perfect alternative of milk.
Fortified soymilk may contain the same amount of calcium as cow's milk on the label, but you have to drink more of it to get the same benefits because the amount of calcium the body absorbs is less. Research has shown that the body absorb about 25 percent less calcium from soymilk than from cow's milk. Since soy beverages are naturally low in calcium (about 10 milligrams per serving), manufacturers fortify them with calcium salts to boost the calcium content. However, the amount of calcium salts added is not regulated and may vary from 80 to 500 milligrams a serving. A serving of milk (8 ounces) contains about 300 milligrams of calcium. It would take 500 milligrams of calcium in an 8-ounce serving of fortified soymilk to equal the calcium in a glass of cow's milk.