Data from almost 75,000 women collected over 24 years do not support the hypothesis that calcium supplements may increase the risk of cardiovascular disease in women, researchers report.
Moreover, calcium supplements were associated with a decreased risk of coronary heart disease (CHD), according to findings published in Osteoporosis International .
Commenting on the new study, Duffy MacKay, ND, senior vice president, scientific & regulatory affairs for the Council for Responsible Nutrition (CRN), said: “Calcium is an essential nutrient most widely used for its bone health benefits, and government data show most Americans don’t get enough. We encourage continued studies on calcium’s safety and benefits, but this study should help women feel confident that calcium supplements are an appropriate choice if they are not getting enough from food alone.”
Osteoporosis has been described as a silent killer, and recent data from the National Osteoporosis Foundation showed that approximately 9 million American adults currently have osteoporosis and another 48 million have low bone mass, placing them at increased risk.
An economic report from Frost & Sullivan and commissioned by the Council for Responsible Nutrition (CRN) recently found that supplements of calcium plus vitamin D for all US women with osteoporosis could provide healthcare cost savings of $1.08 billion per year.
Despite the clear benefits of calcium (and vitamin D) for bone health, papers published in journals such as JAMA , Heart , and the British Medical Journal reported significant adverse cardiovascular effects related to excessive calcium intake in different populations, leading to concerns, and even condemnation of calcium supplements by some (the plaques that form in diseased arteries are composed mostly of calcium).
On the flip side, other studies have reported no such links, including a study from Harvard Medical School researchers published in the American Journal of Clinical Nutrition in 2012.
Risk increase or risk reduction?
The new study, led by Julie Paik, MD, from Brigham and Women's Hospital, examined data from the Nurses' Health Study (1984–2008). During the 24 years of follow-up, there were 2,709 heart attacks and 1,856 strokes, and there were no associations between calcium supplement intake and CVD risk.
Indeed, the relative risk of CVD for women taking calcium supplements at a dose of at least 1 gram per day was about 18% lower than for women not taking the supplements. Similar doses were associated with a 29% reduction in the relative risk of CHD, wrote the researchers.
“Our study has several distinct strengths compared to prior studies,” explained Dr Paik, “including the large number of participants, long-term follow-up, large number of cardiovascular events that were confirmed by medical record review, detailed information about diet and other cardiovascular disease risk factors, and repeated assessment of calcium supplement use over the 24-year follow up period.”
“Based on our findings, additional prospective cohort studies examining potential cardiovascular disease risk associated with calcium supplement use are needed,” she added. “Future randomized trials of calcium supplementation, if conducted, should be designed to optimize assessment of cardiovascular events.”
Source: Osteoporosis International
Published online ahead of print, doi: 10.1007/s00198-014-2732-3
“Calcium supplement intake and risk of cardiovascular disease in women”
Authors: J.M. Paik, G.C. Curhan, Q. Sun, et al.