What Does Calcium Do, Anyway?

If you think of calcium as the bone mineral, you're certainly correct, but did you also know it plays a key role in heart health? If you've ever questioned "what does calcium do?," you might be surprised to find out about the complex lifelong process your body goes through with calcium and how many parts of your body the mineral affects.

What Does Calcium Do?

Calcium is the most abundant mineral found in the human body, according to the National Institutes of Health (NIH). We generally associate calcium with the bones (and teeth) because that's where the body stores 99 percent of its calcium.

Calcium performs many other fascinating functions, however. It acts as a cellular gatekeeper, so to speak, allowing insulin and other hormones into individual cells. Calcium helps cells release chemicals that enable cellular communication, and also helps the blood to clot.

How Do the Bones Develop?

Of course, calcium plays a key role in bone tissue development. An embryo's first bone develops at about six weeks of age, when the collarbone forms. After a baby is born, the bones accumulate calcium at a rapid pace to achieve density. This process continues throughout childhood and young adulthood. Around age 21, the body stops accumulating calcium for bone storage and reaches what the Centers for Disease Control and Prevention calls "peak bone mass." At this point, the skeleton is considered a mature structure.

What Happens to the Bones as We Age?

Bone cells are constantly being broken down and replaced. This process, called remodeling, helps keep our bones strong. However, beginning in adulthood, the human body begins extracting calcium from bone tissue. This process causes a gradual decline in bone density. According to NIH, bone loss accelerates in women after menopause and in people who do not consume enough calcium. In severe cases, loss of bone density is called osteoporosis.

The Controversy Over Calcium Supplements

Because of the close relationship between calcium and bone density, the common thinking has been that taking calcium supplements will improve bone density and reduce fractures in older age. This has not necessarily proven to be the case.

Clinical studies have shown calcium supplementation does improve bone density. However, a 2010 study from the Clinical Journal of the American Society of Nephrology shows that research has not yet demonstrated a clear correlation between calcium supplementation and reduced incidence of bone fractures. Equally troubling, a paper published in 2012 in the BMJ's Heart peer-review journal suggested a relationship between calcium supplementation and problems with cardiovascular health.

Should You Increase Your Calcium Intake?

One fact scientists can agree on: Everyone needs to get enough calcium. We know it is an essential nutrient for overall health and well-being — remember, it serves many purposes in the body, including keeping the heart healthy. NIH offers a very comprehensive fact sheet on calcium that includes the latest research findings.

You should not necessarily begin taking calcium supplements on your own. For one thing, calcium can interfere with the actions of many medications. To stay safe, you should consult your doctor about whether (and how) you should increase your calcium intake. You can help with this decision-making process by keeping a food log. This will provide information about your current level of calcium intake and the sources you get calcium from.

Preserving your bones and protecting your heart are two admirable health goals, but before you supplement, be sure to check with your doctor.