Doctors say study is flawed: heart risk with calcium supplements

By Robyn Nazar, RN BSN

The latest headline this week has many women worried about whether or not their post-menopausal calcium supplements are actually putting them at a greater risk for a heart attack and stroke. However, experts are questioning the strength of the study and advising women to continue with current treatment courses until further information is made available.

The WHI Study

This sudden attention to the possible link between calcium supplements and cardiovascular events was brought on by a study published in the April 19, 2011 edition of the British Medical Journal. Researchers on the study conducted a reanalysis of the data supplied by the Women’s Health Initiative, which was comprised of medical information from over 36,282 postmenopausal women. The researchers used the data to assess whether or not the personal use of calcium and vitamin D supplements lead to an increased risk for heart attack and stroke in women.

In the concluding portion of the report the study’s authors stated, “Calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction, a finding obscured in the WHI CaD Study by the widespread use of personal calcium supplements. A reassessment of the role of calcium supplements in osteoporosis management is warranted.”

This conclusion has alarmed many women who are taking calcium supplements, leading them to question whether or not they should discontinue this important preventive health treatment for osteoporosis.

Study May Be Flawed

Experts warn, however, that this study is flawed and misleading and therefore current practices should not be changed on the basis of this study. In discussion portion the authors report they admitted this much.

“By itself, this analysis of the WHI CaD Study data does not provide definitive evidence of an adverse effect of calcium and vitamin D on cardiovascular events,” wrote the authors. “In the entire WHI cohort there was no significant interaction between calcium and vitamin D, personal calcium supplement use, and mortality—and therefore no evidence of a difference in mortality risk with calcium and vitamin D in the subgroups defined by personal calcium use.”

Physicians, however, are now concerned that the media attention drawn to this study will lead women to stop taking their calcium supplements.

Doctor’s Caution Against Discontinuing Use of Supplements at This Time

Dr. Steven Schnur, cardiologist from Elite Health Medical Group in Florida weighed in on this issue, “The study performed a meta analysis which has inherent flaws while the benefit of calcium supplementation to prevent osteoporosis is well established therefore many more studies will need to be performed in order to come to any definitive conclusion.”

Cardiologist Dr. Perry Krichmar from Elite Health also added, “I don’t believe that all women should stop taking their calcium supplementation until we have further comments by the American College of Cardiology and the American Heart Association. We need more studies to determine if there is a subset of patients that are a higher risk than the average patient taking calcium supplements, therefore the data needs to be further broken down and evaluated.”