Calcium is a vital element in the bloodstream, but when people do not consume enough calcium in their diets, the body will rob internal sources of calcium such as the bones. Over time, the exploitation of bone's calcium may lead to serious bone problems like osteoporosis. Ninety-nine percent of calcium in the body is found in the bones. The other 1 percent is in the blood and cells. The amount necessary is small, but it is always maintained.
Bones are always in a state of change called remodeling.
Remodeling breaks down existing bone and deposits new bone in its place. Milk and milk products are the best sources of calcium. Few other foods provide such a concentrated source of calcium that is as readily available for absorption as do milk and milk products. Milk's calcium absorption is about 30 percent. Some foods reduce calcium absorption and actually increase the loss of calcium in the urine.