BMJ Study Links Calcium to CVD Death

WASHINGTON, D.C.A new study published in the British Medical Journal links high calcium intake to higher death risks in women, especially related to cardiovascular disease (CVD).

Researchers from Uppsala University in Sweden studied more than 61,000 Swedish women using the Swedish Cause of Death Registry and  the Swedish Mammography Cohort (BMJ2013;346:f228). The lowest quartile averaged 572 mg/day of calcium intake, compared to 2,137 mg/day for the highest quartile. During 19 years of follow-up, 17 percent of the women died, with 33 percent of deaths caused by CVD, 16 percent from heart disease and 8 percent from stroke. The researchers noted the highest rates of death among women with calcium intake 1,400 mg/day or higher; women with calcium intake below 600 mg/day also had higher death rates.

However, industry experts are reminding consumers that calcium is still an essential nutrient for bone health " This study doesnt change that fact and also demonstrates there are potential issues with too little calcium. The Institute of Medicine recommends women over 50 should obtain 1,200 milligrams of calcium daily, but also advises of a Tolerable Upper Intake Level (UL), which is the point at which no adverse effects are known, of 2,000 mg dailyfrom all sources, including food and supplements. This study does not change those recommendations, nor should it," said Taylor Wallace, Ph.D., senior director, scientific and regulatory affairs, Council for Responsible Nutrition (CRN).  

Wallace also explained the study did not demonstrate a cause-and-effect relationship between calcium and mortality.

"There are some very specific flaws in this study, beginning with the fact that it was not set up to address the question it answered," he said. "Further, it did not adjust for the role of hormone replacement therapy (HRT), and since science has gone back and forth as to whether HRT helps or hurts the heart, the jury is out as to how this might influence the findings."  

This is the second study in February to raise negative concerns about calcium and CVD death. A recent study in Journal of American Medical Association linked supplemental calcium to higher risk of CVD death in men. However, industry organizations raised concerns over the study's inappropriate design and use of large-scale cohorts designed for cancer incidence, not CVD death.