Scientists from Johns Hopkins Medicine and other institutions report that while a calcium-rich diet may benefit the heart, calcium supplements could increase the risk of plaque buildup in the arteries and heart damage.
Heart disease occurs when the coronary arteries cannot supply the heart with enough blood, oxygen, and nutrients. In most cases, cholesterol deposits — known as plaques — are responsible.
These plaques narrow the arteries and reduce blood flow to the heart, which can lead to chest pain, shortness of breath, or even a heart attack.
Plaque buildup causes the inner walls of the arteries to gradually narrow, a process called atherosclerosis. Coronary artery disease develops when this buildup affects the arteries that supply blood to the heart.
Calcium is essential for building and maintaining strong bones. It also plays important roles in heart function, muscle contraction, and nerve signaling.
Some research suggests that calcium, especially when combined with vitamin D, may offer benefits beyond bone health, including possible protection against cancer, diabetes, and high blood pressure.
However, recent studies have raised concerns that calcium supplements may be linked to a higher risk of heart disease.
In the new study, researchers examined the relationship between calcium intake — from both diet and supplements — and atherosclerosis.
They measured coronary artery calcification, which refers to calcium deposits in the walls of the coronary arteries. This condition often develops after years of plaque accumulation and is a marker of atherosclerosis.
The study included 5,448 participants who did not have heart disease at the start. Researchers assessed calcium intake from food using dietary questionnaires and from supplements through medication records.
Women generally consumed more calcium than men, the researchers found.
Overall, higher total calcium intake was associated with a lower risk of atherosclerosis. However, the use of calcium supplements was linked to an increased risk of heart disease events.
The findings suggest that obtaining calcium through diet may benefit heart health, whereas relying on supplements could increase cardiovascular risk.
The study was conducted by Erin Michos and colleagues and published in The Journal of the American Heart Association.
