Calcium is a very important component of muscle and nerve function; however, most of the calcium in the body is found in the bones and teeth, according to the Office of Dietary Supplements. Many people take calcium supplements to protect their bones from osteoporosis and fracture. Recent research has associated taking calcium supplements with heart attack risk; if you are taking calcium, you should be aware of any risks.
Calcium Supplementation
Adults need approximately 1,000 mg of calcium each day, while postmenopausal women may need between 1,200 to 1,500 mg, according to the University of Michigan Health System. Other people who may also need calcium supplementation include lactose-intolerant people and strict vegetarians; however, many older men also take the supplement as well, as noted by the Office of Dietary Supplements. The amount of calcium in supplements ranges from 200 mg to 600 mg and may include vitamin D in the tablet.
Calcium and Increased Heart Attack Risk
A recent study raised some concerns for heart health for people who take calcium supplements. In a 2010 article published in the "British Medical Journal," Ian Reid and colleagues reviewed previous studies about calcium supplements and found that people who take calcium without vitamin D supplementation had a higher risk of heart attacks. Then, a 2011 study published in the "British Medical Journal" by Reid and colleagues found that calcium -- with or without vitamin D -- modestly increased the risk of heart attacks and strokes. Other researchers, like Bo Abrahamsen, noted in an editorial in the same issue of the "British Medical Journal" that more research is needed to clarify whether there is a risk and how large it is, since so many people are using calcium supplementation. These people may already be at higher risk for heart disease.
Suspected Reasons for Calcium and Heart Problems
Theories about why calcium may increase the risk of heart disease vary. Reid and colleagues suggested that the calcium may lead to additional hardening of the arteries, as noted in an April 2011 article by Rob Stein in the "Washington Post." The researchers also wondered if the extra calcium may lead to blood clot formation. Another researcher, Elizabeth J. Vavasour from Health Canada, wrote a reply in "The British Medical Journal" that questioned whether low levels of vitamin K when the calcium supplementation is started play a role in heart attack risk. More research will help answer these questions so that people taking calcium supplements can make informed decisions.
Should You Take Calcium Supplements?
Since the association between calcium and heart attacks is unclear, you may wonder if you should still take calcium supplements. The recommendations for taking calcium supplements for people who have osteoporosis or risk factors for the condition -- including thinness, White or Asian ethnicity, female sex, or family history -- have not changed due to these reports, as noted by the MayoClinic.com. You should speak with your physician or another health-care professional about your personal case; you should not discontinue your calcium supplements without confirmation from your doctor.
References
- "British Medical Journal"; Calcium Supplements With or Without Vitamin D and Risk of Cardiovascular Events: Reanalysis of the Women's Health Initiative Limited Access Dataset and Meta-Analysis; MJ Bollard, IR Reid, and colleagues; 2011.
- MayoClinic.com: Calcium Supplements: A Risk Factor for Heart Attack?
- "British Medical Journal"; Vitamin K Status of Study Participants Might Clarify Calcium-Cardiovascular Risk Association; Elizabeth J Vavasour; April 2011.
- "Washington Post"; Calcium Intake, Higher Heart Risks Are Linked in Study; Rob Stein, April 2011.
- "British Medical Journal"; Effect of Calcium Supplements on Risk of Myocardial Infarction and Cardiovascular Events: Meta-Analysis; MJ Bollard, IR Reid, and colleagues; 2010.
- University of Michigan Health System: Calcium and Vitamin D
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