A new study finds supplementing with calcium may slightly increase risk of heart attacks. Researchers suggest a review of current calcium recommendations.
A study published in the British Medical Journal found that calcium supplements commonly prescribed to benefit skeletal health, may increase the risk of a heart attack and cardiovascular events such as stroke, in healthy older women by 20% to 30%.
Calcium and Osteoporosis
While the increased risk is small, and some researchers say the findings are unnecessarily alarmist, given the widespread use of calcium supplements to help prevent osteoporosis, even a small risk within a large population could become a health burden, warns the study’s lead researcher Dr. Ian Reid.
Calcium supplementation has proven to provide only minimal benefit to increase bone density and to prevent fractures in women. As a result of its limited use for osteoporosis patients and the new heart risk findings, Reid suggests the current supplement recommendations be re-assessed.
In an editorial published with the study, cardiologist John Cleland of the U.K.’s Hull York Medical School called the analysis “concerning but not convincing.” Like Reid however, Cleland remains cautious. “Given the uncertain benefits of calcium supplements, any level of (heart) risk is unwarranted.”
Council for Responsible Nutrition Questions Implications
Dr. Andrew Shao, senior VP, scientific & regulatory affairs with the Council for Responsible Nutrition (CRN) says in a press release for CRN that the warnings have been overstated and dilute the importance of calcium. Calcium’s role in building and maintaining bone is vital says Shao, and to prevent osteoporosis. “The results from this meta-analysis does not undermine the value calcium supplements offer to those concerned with maintaining or increasing bone density, as years of research shows these products do,” he says.
The problem explains Shao, is the meta-analysis only included 15 randomized trials on calcium, rather than the available 300. Moreover, seven of the 15 trials had no, or incomplete data on cardiovascular outcomes and the study excluded studies that combined calcium with vitamin D. “This analysis should not dissuade consumers, particularly young women, from taking calcium supplements. They should talk with their doctors about their current and long-term needs and determine how much calcium they are getting from their diets, and supplement accordingly, likely in combination with vitamin D,” says Shao.
Vitamin D and Heart Health
Vitamin D, actually a secosteroid hormone, is gaining increasing attention among researchers. Once largely associated with bone health, studies indicate vitamin D may play an essential role in a wide array of key body functions including immunity, cancer prevention, and heart health.
“Vitamin D deficiency is an unrecognized, emerging cardiovascular risk factor, which should be screened for and treated,” says researcher James H. O’Keefe, MD, director of preventive cardiology at the Mid America Heart Institute in Kansas City, Mo., in a news release. “Vitamin D is easy to assess, and supplementation is simple, safe and inexpensive.”
The December 2008 issue of The Harvard Heart Letter reported on the link between vitamin D and heart health, writing that calcium deposits that stiffen the arteries are more likely to develop in people with low levels of vitamin D and cause coronary artery disease. Like low magnesium, a D deficiency contributes to high blood pressure, a risk factor for heart attack and stroke.
Jennifer Warner in her WebMD article “Too Little Vitamin D Puts Heart at Risk,” writes that researchers are finding a growing body of evidence to suggest a vitamin D deficiency increases the risk of heart disease and is linked to other, well-known heart disease risk factors such as high blood pressure, obesity, and diabetes.
Magnesium and Heart Health
Another unsung hero involved in heart health is magnesium. Dr. Carolyn Dean, Medical Director of the Nutritional Magnesium Association and author of several books including The Magnesium Miracle, has long warned doctors and the public against over promoting calcium and under promoting magnesium.
Magnesium is a mineral that plays a critical role in heart health and balances the effects of calcium. Most calcium-magnesium formulations however, have a 2:1 (or higher) ratio. Dr. Dean recommends the inverse, 2:1 magnesium.
Andrea Rosanoff, Ph.D.Director with the Center for Magnesium Education & Research writes in her book The Magnesium Factor, “The most important marker for impending heart disease is a low magnesium to calcium ratio in the cells.” Rosanoff’s co-author, Dr. Mildred Seelig writes, ”While several essential nutrients are imperative for heart and blood vessel health, the vast research on low magnesium and its impact on heart health has gone unheeded, so much so that much of the heart disease seen today is a direct result of low magnesium consumption.”
In recent decades calcium supplementation has been heavily promoted to prevent osteoporosis, build bone density and prevent fractures, yet results have been disappointing. Calcium, a new finding suggests, may actually increase the risk of heart attack. Yet magnesium and vitamin D once largely in the shadow of calcium, are gaining attention for their role in the prevention of a wide array of diseases and to improve overall health functioning, including heart health.
Boyles, Salynn, “Calcium May Increase Heart Attack Risk, WebMD Health News. July 29, 2010.
Bolland MJ, Avenell A, Baron JA, Grey A, Maclennan GS, Gamble GD, Reid IR., “Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis.” British Medical Journal, 2010 Jul 29.
Rosanoff, Arlene, Ph.D. and Seelig, Mildred. The Magnesium Factor, Penguin, 2003.
“Vitamin D deficiency bad for the heart, bones, and rest of the body,” Harvard Heart Letter, December 2009, Harvard Health Publications, Harvard Medical School.
Warner, Jennifer, “Too Little Vitamin D Puts Heart at Risk.” WebMD Health News. Dec. 1, 2008.
Disclaimer: The information contained in this article is for educational purposes only and should not be used for diagnosis or to guide treatment without the opinion of a health professional. Any reader who is concerned about his or her health should contact a doctor for advice.
Copyright Laura Owens. Contact the author to obtain permission for republication.