Dietary calcium through calcium-rich foods is good for you; however, taking excessive amounts of calcium supplements may harm the heart, that according to 10-year study by researchers at Johns Hopkins University and other universities. The findings, published Oct. 10 in the Journal of the American Heart Association, analyzed data of more than 2,700 patients from the Multi-Ethnic Study of Atherosclerosis, a longitudinal study of risk factors for cardiovascular disease. Forty-six percent of them took calcium supplements. By looking at calcium consumption in year one and year 10, researchers concluded that those who took calcium supplements had a 22 percent increased likelihood of calcium buildup in the coronary arteries, indicating heart disease development. Researchers said, however, a diet that is high in calcium-rich foods appears to be protective.
“They really found this problem in people who were taking more than 1400-1500mg a day,” Dr. Toniya Singh, a board member of the American Heart Association and a partner at St. Louis Heart and Vascular, said. “When you take a high dose of calcium, it is shown that it doesn’t really go straight to your bones. Some of it gets deposited in your soft tissues and in your blood vessels.”
Smaller doses throughout the day, like you would get through eating and drinking, may be a better way, she explained.
Sometimes people think ‘if my bones are weak, I can take extra calcium, that will make them stronger’ – even more than the doctor suggested. But that’s just not how that large dosage of calcium works in the body,” she said. “So, more is not always better.”
Several studies evaluating the relationship between calcium supplementation and cardiovascular risk produced mixed results, cardiologist Dr. Justin Sadhu said.
“Some have shown that calcium supplementation is associated with increased cardiovascular risk whereas others have not found an association,” said Sadhu, of Washington University and Barnes-Jewish Hospital. “There is not yet consensus regarding the safety of calcium supplementation.”
“I think unfortunately, a lot of people take supplements that are available over-the-counter, thinking they are safe and that there is not any toxicity associated with them, so I think it is very important that if you are on any supplement, that you discuss with your doctor that you are on that supplement.” Dr. Singh said.
Furthermore, people may not realize how much calcium they are already getting, through supplements, multivitamins and in their diet for example.
Doctors recommend calcium supplements to adults to reduce the risk of brittle, porous bones due to osteoporosis.
“Postmenopausal women and adults with low bone density (osteoporosis or osteopenia) often take calcium supplements with the goal of reducing the risk of fractures,” Dr. Sadhu explained. “In most cases, the calcium is taken with vitamin D.”
Persons who are lactose intolerant are another group that may take calcium supplements, Dr. Singh said.
If you are currently taking calcium supplements, both doctors said talk to your doctor about your risks and benefits of calcium supplementation.
Dr. Sadhu said, “For someone without a strong reason to be on a calcium supplement, I would discuss the possible association with cardiovascular risk so that he/she could make an informed decision.”
Additionally, Dr. Singh reminded to “be aware of doses of the supplements you are taking and bring in your bottles of supplements. It may make it easier for you to have a discussion.”
There are other ways of having high amounts of calcium in the bloodstream.
“In day-to-day practice, the common reasons for having high calcium would be kidney disease, parathyroid disease or calcium supplements,” Singh said.
If you eat a balanced, healthy diet, you may already get enough calcium.
“I would advise my patients that eating a healthy, balanced diet is likely superior to trying to obtain nutrients via multivitamins or other supplements,” Dr. Sadhu said. “Natural dietary sources of calcium include milk, yogurt, cheese, kale, and broccoli.”
Fortified cereals and many plant-based foods are good sources of calcium. For a chart of calcium-rich foods, visit http://bit.ly/22KsQ7X.
