Several recent reports claim that calcium supplements may increase the risk of a cardiovascular event. However, a University of Waterloo professor dismisses these claims and encourages continued use of them.

Osteoporosis and low bone mineral density (BMD) are major causes of fragility fractures and associated morbidity and mortality. With the aging of the population, the incidence of this chronic disease is expected to grow significantly. Ensuring adequate calcium and vitamin D intake is one way to help increase bone mass and delay the development of osteoporosis.

Updated Canadian clinical practice guidelines recommend a total daily intake of elemental calcium from diet and supplements of 1200 mg for all individuals older than 50 years. The Institute of Medicine refines it further to 1000 mg for men aged 51-70, 1200 mg for women aged 51-70, and 1200 mg for all individuals older than 70 years.

Seniors may need to take supplements to achieve the recommended intake of calcium. The third National Health and Nutrition Examination Survey reports that approximately 43% of the US population reported use of calcium supplements. This number grows close to 70% in older females, while only 12% of patients 71 years or older met the recommendation for adequate intake despite use of supplements.

Supplemental calcium and vitamin D have been demonstrated to improve BMD and decrease the risk of
fractures. However, recent reports raise concerns that calcium supplements may increase the risk for cardiovascular events like myocardial infarction, coronary heart disease, stroke, coronary revascularization, hospitalized angina, heart failure, or transient ischemic attack.

To address this concern, Dr Carlos H Rojas-Fernandez (Schlegel Research Chair in Geriatric Pharmacotherapy, Schlegel-University of Waterloo Research Institute on Ageing & School of Pharmacy, University of Waterloo, Ontario, Canada) studied all the available research to assess the risk and published his findings in The Annals of Pharmacotherapy. 

Dr Rojas-Fernandez concluded that the studies were not robust enough to challenge current clinical practice. “At this time, then, the benefits of calcium given with vitamin D as seen from the balance of the evidence on bone health outweigh the cardiovascular risks,” says the professor.  Studies do show that dietary calcium is inversely associated with mortality from ischemic heart disease in elderly women and to have no association with cardiovascular risk in men.

“People should thus be encouraged to continue to obtain calcium from their diet and should be counseled to include calcium supplements if necessary to obtain a total daily intake of elemental calcium of 1000-1200 mg, consistent with current guidelines,” consoles Dr Rojas-Fernandez.  “People should also be encouraged to supplement their diet with sufficient vitamin D to achieve optimal vitamin D status.” In Canada, guidelines suggest daily intakes of 400-1000 IU for low risk and younger adults and 800-2000 IU daily for adults older than 50 or those at high risk for vitamin D deficiency.