Calcium and the heart function are closely linked together. When your body has healthy levels of calcium in the blood, calcium affects your heart rate to keep blood flowing and your organs operating correctly. This mineral is essential for many of your body's day-to-day needs.
Calcium's Effect on the Heart
When you think of calcium, you probably think of its role in strengthening your bones and teeth — which is where 99 percent of the calcium in the human body can be found. But that's not all this mineral does.
Calcium also helps the heart work properly and enables blood to clot, which is why it's present in low levels in your bloodstream. Typically, the body self-regulates the amount of calcium in the blood, releasing or absorbing calcium in the bones to keep blood calcium levels in a normal range.
Your blood pressure is also affected by calcium, which enables blood vessels to tighten and relax at different times. All in all, calcium and the heart function are vitally tied together, and it's important to consume a consistent amount of this mineral in order to maintain your heart health.
Calcium Levels and Heart Disease
Too much or too little calcium in the blood can be a problem. When blood calcium levels grow higher than normal, a condition called "hypercalcemia" occurs, which can lead to serious complications if left unaddressed. Hypercalcemia is typically a result of an issue in the parathyroid glands or certain forms of cancer, and it can be spotted during a routine blood test.
In contrast, "hypocalcemia" occurs when there is not enough calcium in the blood to keep your body functioning normally. It's also connected to problems in the parathyroid hormone or sometimes a deficiency in vitamin D. It often happens in patients who are chronically ill with other conditions such as pulmonary disease and heart failure.
When your calcium levels are outside the normal range, it may put undue pressure on your heart and lead to problems down the road. This is one reason why routine blood tests are important for early detection of calcium levels that are too high or too low.
Calcium Supplements and Heart Disease
Since the body cannot produce calcium on its own, some people turn to calcium supplements to help them consume the desired amount. The recommended intake of calcium depends on your age and biological sex, with certain people like elderly women and breastfeeding mothers needing more calcium than others.
Most adults need about 1,000 milligrams of calcium per day, which can be consumed through foods like dairy products, fish and tofu. But for people with low calcium levels who want to add more calcium into their diet, calcium supplements are an option.
Harvard Health Publishing estimates that 43 percent of people in the United States take supplements that contain calcium. But are calcium supplements and heart disease connected? Not directly, but some studies have noticed a link between the use of calcium supplements and risk of heart disease.
In October 2017, a study in the Mayo Clinic Proceedings journal linked low calcium levels to increased risk of cardiac arrest, providing support for the idea of taking calcium supplements to raise blood calcium. But these supplements are controversial, and a study published in the October 2016 issue of the Journal of the American Heart Association linked calcium supplements with heart problems due to buildup of plaque in the arteries.
Others have found no correlation between calcium supplements and heart disease. But what most medical professionals agree on is that calcium is better consumed through food than pills, unless you've been directed otherwise by your doctor. Elderly people and those who suffer from weakened bones may need to supplement calcium to stay healthy, but for the majority of adults, it's not necessary.
Read more: The 14 Best Foods for Your Heart
Calcium and Irregular Heartbeat
Cardiac arrhythmia, or irregular heartbeat, is caused by a disruption of the heart's normal functioning and is among the leading causes of sudden cardiac death in the United States. When calcium is too low or too high, the blood vessels are less easily able to widen and narrow, which can lead to an irregular heartbeat.
Calcium isn't the only mineral that affects your heart function. According to the American Heart Association, potassium and magnesium are also crucial building blocks in your heart's healthy operation. But all three of these minerals can cause irregular heartbeat if they are found to be too high or too low in the bloodstream.
The easiest way to help regulate calcium levels in your blood is to maintain an active lifestyle and stay hydrated. When your body is constantly moving, your digestive system is better able to break down the calcium you consume and send it to the right places — the bones, muscles and blood.
A sedentary lifestyle won't do any favors for your heart health, so the more you can move your body, the better it will be able to regulate calcium on its own. If you ever sense that your heart is beating irregularly, see a doctor as soon as possible to get to the root of the problem.
Changing Your Calcium Intake
Before you add or take away calcium supplements from your diet, consult with your health care provider. It might seem like a logical solution to eat more or less calcium to regulate your body's calcium levels, but this isn't always the case.
There's actually no proven direct link between the calcium you consume and the level of calcium buildup in your body. And while you shouldn't take calcium supplements without the approval of your doctor, you also shouldn't stop taking them unless you've been instructed to do so.
Without sufficient calcium, your body will not be able to stay strong and robust. Likewise, too much calcium hurts your organs' ability to function. Routine blood tests are important to help detect early signs of irregular calcium levels, so you can determine the cause and decide the best way to move forward.
- National Academies Press: "Dietary Reference Intakes for Calcium and Vitamin D"
- University of Michigan Medicine: "Calcium (Ca) in Blood"
- Harvard Health Publishing: "Calcium and Heart Disease: What Is the Connection?"
- Harvard Health Publishing: "Key Minerals to Help Control Blood Pressure"
- MedlinePlus: "Hypercalcemia"
- Canadian Family Physician: "Hypocalcemia"
- American Family Physician: "Undiagnosed Vitamin D Deficiency in the Hospitalized Patient"
- National Institute of Health: "Calcium"
- Mayo Clinic Proceedings: "Serum Calcium and Risk of Sudden Cardiac Arrest in the General Population"
- Journal of the American Heart Association: "Calcium Intake From Diet and Supplements and the Risk of Coronary Artery Calcification and its Progression Among Older Adults: 10‐Year Follow‐up of the Multi‐Ethnic Study of Atherosclerosis (MESA)"
- Endocrinology and Metabolism: "Calcium and Cardiovascular Disease"
- Clinical Medical Insights: Cardiology: "Calcium Dynamics and Cardiac Arrhythmia"
- Stanford University Medical Center: "Hypercalcemia Patient Education"
- Harvard Health Publishing: "Calcium Beyond the Bones"
- American Heart Association: "Understand Your Risk For Arrhythmia"