Taking Calcium: What's a Woman to Do?
You may want to think twice before reaching for those calcium tablets. In 2010, researchers threw women of a certain age into a tizzy with research showing that calcium supplements may hurt the heart while helping bones. Another study, published more recently in 2012, also suggested an association between the supplements and heart attack and stroke risk.
The news unleashed widespread consternation, since many primary care physicians routinely advise menopausal women to take calcium to prevent osteoporosis.
Recent clinical trials followed people who took calcium supplements of 500 mg or more without Vitamin D.* The results of the trials suggest a 31 percent increase in the risk of heart attack among participants. These results echo findings from research conducted in 2006 and 2008 among healthy, older women who took calcium supplements.
More Studies Needed
While the news may not be as dire as it sounds, some doctors are now advising women to replace calcium supplements with yogurt, broccoli and sardines.
“Calcium is often recommended for osteopenia or osteoporosis, but several papers have suggested a possible increase in the risk of heart attack in women taking calcium supplementation," says Loryn Feinberg, MD, a cardiologist in the CardioVascular Institute at Beth Israel Deaconess Medical Center and director of its Women's Cardiovascular Health Program. "This has not been proven in large, randomized clinical trials, but I think we need to be cautious about administration of supplements, especially in women with coronary artery disease (CAD) or those at elevated risk of developing CAD. If you do require calcium, I think you should obtain as much from dietary means, if possible, and try to limit the supplements. If supplements are needed, try to spread out the dose throughout the day rather than taking a large dose all at one time.”
At the same time, Feinberg points out, "We need future studies to look at this more closely. For example, the trials involved calcium supplements without Vitamin D. We have seen findings suggesting that Vitamin D can lower the risk of heart disease, and there may indeed be a relationship between Vitamin D deficiency and cardiac events."
Food Sources are Best
The good news is that the studies suggesting that calcium raises the risk of heart attacks point solely to calcium supplements.
"Calcium obtained directly from food sources show no such risk," says Feinberg. "In fact, there is a suggestion that women who consume adequate dietary calcium have a lower risk of cardiac events than those who do not.”
Given the fact that calcium supplements only have a modest effect on increasing bone density, Feinberg recommends obtaining calcium through food rather than supplements.
"Calcium obtained from dietary sources is best and offers better absorption," she says.
Food sources for calcium include:
- Dairy: yogurt, low fat cheese and milk
- Produce: spinach, kale, broccoli, turnip greens, bok choy, black beans, oranges
- Protein: sardines, salmon, clams
- Other: sesame seeds, almonds
In addition, Feinberg counsels women to avoid smoking cigarettes or being underweight, since both can reduce bone density. She also advises other methods to strengthen bones, including adequate intake of vitamin D and participation in weight-bearing exercise.
"Taking advantage of opportunities for weight-bearing exercise may be easier than you think," Feinberg says. "You can strengthen bone density through walking, yoga, dancing, golf, tennis and lifting weights."
*Clinical Trials conducted jointly by the University of Auckland, New Zealand; University of Aberdeen, UK; and Dartmouth Medical School, NH, USA.
Above content provided by the CardioVascular Institute at Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted January 2013