Calcium is an important mineral for the human body. It is essential for muscle contraction, but also essential to the structure and health of the bones. Bones are continually remodeling and reforming, and calcium is a vital part of this process. People therefore need a certain daily amount of this mineral, since without it the bones become thin.
Bones are structured to provide strength and protection but also to allow for movement. In addition, the structure allows the bones to serve as a reservoir for several minerals, including calcium, because calcium quickly moves between the bone and the blood. Approximately 30 percent of bone is called the organic or living material and is made of collagen and protein, the other 70 percent is mainly made of calcium and phosphate, although there is some potassium, sodium and magnesium.
Bones are continually remodeling and this process involves two types of cells. The osteoblasts build the organic material of the bone when sent the signal to do so. A few days later, calcium and phosphate start to make the new area hard. At the same time, there is a breakdown of bone by the osteoclasts, as explained by Corwin. These cells break down a small section and leave, then the osteoblasts arrive to fill in the area with new bone. New strong bone, which is mainly calcium, continually replaces areas of old, weak bone.
People who are 19 to 50 years old should have 1,000 milligrams of calcium every day. Those over 50 should have 1,200 milligrams on a daily basis. To be able to use calcium, the human body also must have enough vitamin D, because vitamin D stimulates the osteoblasts to build bone and stimulates the absorption of calcium from the intestines. Having large amounts of vitamin D without enough calcium can increase the breakdown of bone because the body will try to increase calcium levels.