But I want to point out an interesting fact about chocolate milk... and is roughly true for milk in general. 1 cup of chocolate milk has 9 grams of protein in it.
So much protein in fact that it makes the calcium in the milk moot. (If you drink protein and calcium together, your body can only absorb so much of the calcium because the protein acts a blocker.) So you really aren't getting much calcium when you drink milk. There's too much protein in it.
Same goes when you any meal containing decent amounts of protein in it (ie. a bacon cheeseburger)... if you eat something with calcium in it you really aren't absorbing the calcium. Thus in the case of a bacon cheeseburger you end up absorbing the fat from the cheese, but almost none of the calcium.