How does calcium work?
As with other minerals, the body has an efficient system for keeping the concentration of calcium in the blood and tissues in balance.
This is needed because if calcium concentrations fall too low or get too high, certain organs will fail to function.
The first checkpoint is in the intestines. If you eat too much calcium, or already have enough calcium in your blood, the intestines simply absorb less of the calcium in the food you eat. If your body needs calcium, the intestines absorb more.
Bones are the second checkpoint. If you don’t get enough calcium in your diet, your body may borrow what it needs from your bones. This works for a time, yet continuing withdrawals of calcium from the bone bank can lead to osteopenia and osteoporosis.
A hormone called parathyroid oversees all this calcium activity like a vigilant bank manager, keeping the calcium concentration just right. When your calcium levels fall, this hormone stimulates vitamin D to increase absorption of calcium from the intestines, and to release calcium from the bone bank until a proper balance is restored.
It is an efficient system, but even if you are eating a fair amount of calcium, there are some other factors in your diet and lifestyle which can interfere with the calcium you consume being utilized by your body. We will deal with these factors in a later section of this article.
