"Milk is often pitched as a great source of calcium. It is not. Yes, it has a high calcium content, but the human body is able to utilize very little of it. In fact, because of the way the body deals with milk, consumption of milk actually leaches calcium from the bones. It is a myth that we need milk for calcium. There are many far superior sources of calcium, such as sesame seeds, broccoli, Chinese cabbage, and collard greens. It's worth noting that there's more calcium in three-quarters of a cup of collard greens than in a cup of cow's milk.
The problem with milk is that because of its high sulfur and phosphorus content, your body needs to buffer it with even more internal calcium than you get from the milk itself. Besides, even if the absorption issue was not enough by itself, the 10 to 1 ratio of calcium to magnesium found in milk is too high and devastating to the human body. If you have any doubt about this, just consider the fact that Americans are among the highest consumers of dairy in the world and yet we have one of the highest incidences of osteoporosis in the civilized world!"