Calcium is an essential mineral involved in many critical biological processes, including brain function and bone growth. Elderly women are often advised to take calcium supplements to prevent osteoporosis and decrease the risk of bone fractures. However, results of a wide-scale study completed in 2010 suggest that calcium supplements may increase the risk of heart attack and stroke, leading many doctors to carefully reconsider the use of calcium supplements.
Heart Attack
A large-scale analysis of studies involving calcium supplements and heart disease in over 30,000 women found that calcium supplements increased the risk of heart attacks by 25 to 30 percents, reports a paper published in the May 2010 issue of the British Medical Journal. Calcium supplements were also associated with a 15 to 20 percent increased risk of stroke.
Mechanism
The increased risk of heart attack may result from calcification of blood levels. When high levels of calcium are present in the blood, the calcium can form deposits in soft tissues, such as the heart and blood vessels, a process known as calcification. This calcification may lead to hardening of the arteries, or atherosclerosis, which is a risk factor for heart disease, explains the Linus Pauling Institute of Oregon State University.
Supplements
The benefits of calcium in preventing osteoporosis are well known, and the authors of the recent study do not suggest that people should stop taking all calcium, HealthFinder.gov reports. Instead, the authors urge people and their doctors to carefully examine the need for calcium supplements on an individual basis.
Alternatives to Supplements
One way to avoid calcium supplements is to eat plenty of foods that contain high levels of calcium. Dairy products, such as milk, cheese and yogurt, are well-known sources of calcium. Other foods, including white beans, spinach and rhubarb also contain high amounts of calcium, while kale, bok choy, broccoli, red beans and pinto beans contain smaller, but still significant, amounts. In addition, many of those foods contain high levels of vitamin K and vitamin D, which are also important for bone health, reports Harvard Health Publications.
References
- "British Medical Journal"; Effect of Calcium Supplements on Risk of Myocardial Infarction and Cardiovascular Events: Meta-Analysis; Mark J. Bolland, et al.; July 2010
- Healthfinder.gov: Women Taking Calcium Supplements May Risk Heart Health, Researchers Say; Amanda Gardner; April 2011
- Harvard Health Publications: Could Too Much Calcium Cause Heart Disease; P.J. Skerrett; August 2010
- Linus Pauling Institute at Oregon State University: Calcium
