BALTIMORE, Oct. 12 (UPI) -- People who take calcium in the form of supplements may face a higher risk for heart disease, Johns Hopkins researchers suggest in a new study.
During the study, researchers analyzed 10 years of medical tests on over 2,700 people. According to the authors, calcium supplements may contribute to the plaque buildup in arteries associated with heart disease in addition to heart damage. Calcium-rich foods, by contrast, were found to be beneficial. The findings were published in the Journal of the American Heart Association.
"When it comes to using vitamin and mineral supplements, particularly calcium supplements being taken for bone health, many Americans think that more is always better," author Erin Michos said in a press release. "But our study adds to the body of evidence that excess calcium in the form of supplements may harm the heart and vascular system."
The study built on earlier heart- and calcium-related scholarship that questioned the substance's effectiveness in older people. According to prior research, the nutrients in calcium supplements often don't make it to the skeleton or are completely excreted in urine. As a person ages, scientists noted, calcium-based plaque fortifies around the aorta and other important blood vessels, increasing the risk of a heart attack.
Participants in the study were between 45 and 84 years old, and were tasked with completing a 120-part questionnaire to detail their dietary habits, which included information on supplements and other drugs. The questionnaire was followed by a cardiac CT scan to measure coronary artery calcium scores. The scans were repeated a decade later, allowing researchers to analyze newly developing heart disease.
Researchers divided the participants into five groups based on total calcium intake, with the greatest number measuring over 1,400 milligrams per day. Supplement users showed a 22 percent increased chance of having coronary artery calcium scores higher than zero.
"There is clearly something different in how the body uses and responds to supplements versus intake through diet that makes it riskier," lead author John Anderson explained. "It could be that supplements contain calcium salts, or it could be from taking a large dose all at once that the body is unable to process."