Cardiologists say new calcium supplement study is no reason to panic

A study recently published in the Journal of the American Heart Association is prompting headlines like "Calcium supplements might hurt your heart."

The new research suggests dietary calcium in the form of supplements, but not calcium-rich foods, might have a harmful impact on the heart.

UAB Assistant Professor in the Division of Cardiology Pankaj Arora, M.D., says there is not a reason to panic.

"How I interpret the study is, with a calcium intake of 400 mg to 1,400 mg, there is no association with coronary artery calcification," Arora said.

Arora says the new study looked at changes in CAC over the span of 10 years in nearly 5,500 adults ages 45-84. Calcium supplements were associated with a 22 percent increase in CAC.

Arora says it is important to note this is association and not causation, and this now needs to be tested in a randomized controlled clinical trial.

Researchers who worked on the study published in the Journal of the American Heart Association say this should give people pause if they are taking calcium supplements. Arora says more research needs to be done.

"We need to make sure there's no gender difference, there are no ethnicity differences, and the message is the same for you and me," he said.

According to the CDC, 43 percent of adults take calcium supplements. Arora says it is still OK to take these supplements in moderation.

"I would tell people excess of anything is bad, so do not take these supplements in excess," Arora said. "I would say it's OK in doses recommended by the Institute of Medicine and American Heart Association."

UAB Assistant Professor of Nutrition Science Beth Kitchin, Ph.D., also has reservations about jumping to conclusions from this study.

"This was an observational study, which are very weak in design, particularly in nutrition research," she said. "This kind of study cannot show cause and effect—only correlations."

Kitchin says the correlation between calcium supplementation and a heart event was very weak—to the point of being almost non-existent.

"The amount of calcium that did show a correlation was way over the amount that we recommend to patients," Kitchin said.

Arora says it is better is to eat a diet that can provide the daily amount of calcium needed and to not rely on dietary supplements. Participants with highest calcium intake from food—more than 1,022 milligrams a day—showed no increase in relative risk of developing heart disease.

Calcium can be received not just from dairy products. Foods likes spinach, broccoli, collard greens and oranges are high in calcium, and can be used as a substitute for dairy.

Coronary heart disease kills more than 370,000 Americans each year, according to the U.S. Centers for Disease Control and Prevention. More than half of women over 60 take calcium supplements—many without physician oversight—to reduce osteoporosis risk.