Your body and calcium

Why our body needs calcium
Calcium is a mineral that is stored in the bones. Nearly all the calcium in the body is stored in bone tissue. But a small amount (around 1%) circulates dissolved in the blood and other body fluids, or is inside our cells. This is needed for

Keeping bones and teeth healthy
Blood clotting
Normal functioning of the brain and spinal cord (central nervous system) and
Keeping our muscles working properly

If your blood calcium level gets too high or too low it can be dangerous. Having too much calcium in the blood is called hypercalcaemia (pronounced hyper-kal-seem-ia). Hypercalcaemia in cancer can be a serious problem for some people. Not having enough calcium is called hypocalcaemia (hypo-kal-seem-ia).

Where the body get its calcium from

Our diet gives us calcium. The foods highest in calcium include

Dairy products such as eggs, milk, butter and cheese – this is where most of our calcium comes from
Green vegetables such as broccoli, spinach and beans
Nuts
Whole grain foods such as bread, rice and cereals

Our bodies absorb calcium from the food we eat through the lining of the bowel. The calcium is stored in the bones. The body controls the amount of calcium in the bloodstream very carefully. When blood levels of calcium fall too low, the bones release calcium into the blood. The amount of calcium absorbed from food in the bowel also increases. And the kidneys get rid of less calcium through the urine. If blood levels of calcium get too high, the opposite happens.

There are 3 hormones in the body that play an important role in this complicated control system. These are
    Parathyroid hormone (PTH) – made by the parathyroid glands
    Vitamin D
    Calcitonin

These hormones help to keep the correct balance of calcium in the blood.
If this balance is upset, the amount of calcium in our blood can get too high (hypercalcaemia) and cause serious problems.

The main causes of hypercalcaemia are