What is Calcium?

It may be a common misconception that we only need calcium for healthy bones and teeth. While it does play an important role in our skeletal system, it also does much more than that. 

Calcium is an electrolyte along with chloride, potassium, sodium, and magnesium.   When electrolytes dissolve inside our body’s fluids, they become charged with electricity and work together to ensure our cells and organs function properly.

What does calcium do?

Calcium is critical for the functions of our nervous, muscular, and skeletal systems. It is so essential that it has its own system of control, one that does not exist for any other element in the body. The parathyroid glandsonly job is to monitor and control that system.

Nervous System

Of all the functions of calcium, the most important is its role in our nervous system. Our nerve cells require electrical currents to travel. Calcium is what our nervous system uses to conduct those electrical impulses. Our entire body relies on the nervous system to function well. Our vital organs, the heart and brain, require the nervous system to survive.

In this image, from Brockhaus, et al. The Journal of Neuroscience, 2018, scientists have altered the neurons so that the calcium receptors emit light (seen as green).  This helps researchers understand the neurons’ function and gives a sense of the role calcium plays in the nervous system.

Muscular system

Muscles require energy in order to contract, and calcium provides this energy. It is through the calcium inside muscle cells that they have the necessary energy to move properly.

Skeletal system

Calcium’s role in the skeletal system isn’t as simple as you may have learned as a child. Calcium doesn’t just go into our bones and make them strong, end of story. Rather, bones serve as an important storage vault for calcium that may end up being needed elsewhere. 

When we need more calcium in our blood (to serve our nervous and muscular systems), the parathyroid glands secrete parathyroid hormone (PTH) to signal the release of calcium from the bones. However, when we have a bit more calcium than our body needs, the parathyroid glands stop releasing PTH and the thyroid gland releases one of its hormones, calcitonin, which signals the body to deposit calcium back into the bones.

Calcium and Hypoparathyroidism

Most people never have to think about calcium levels. But for people who live with hypoparathyroidism, regulating calcium can be an extreme challenge. When calcium levels are low (a condition known as hypocalcemia), it can impact personality, emotions, physical functions, and in severe cases, be life-threatening.

Because undiagnosed or undertreated hypopara can be life-threatening, it is important to know the signs and symptoms of hypoparathyroidism.