Diets high in phosphorus and animal protein can lead to calcium leeching from the bones. Interestingly dairy foods, touted as a good source of calcium such as milk, yogurt, ice cream, and cheese, are also high in phosphorus and animal protein. If the phosphorus in your blood is high, calcium blood levels need to match. If your diet is too high in animal protein, there is a rise in the acidity of your blood and your blood needs calcium buffering to maintain pH balance. In both cases your blood may pull calcium from your bones.