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Effect of calcium supplements on risk of myocardial infarction and

cardiovascular events: meta-analysis.

Bolland MJ et al. BMJ 2010;341:c3691

Page 1 Bolland MJ et al. BMJ 2010;341:c3691

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Background

• Sufficient intake of calcium is essential for bone health• Calcium and vitamin D are considered as basic treatments in

fracture prevention among both osteopenic and osteoporotic patients

• Previous observational studies have demonstrated positive association between high calcium intake and cardiovascular health

• In some recent studies high calcium intake as supplements has been linked to increased risk of cardiovascular events in renal failure

• High intake of calcium is also associated to increased incidence of prostate cancer

www.pronutritionist.netBolland MJ et al. BMJ 2010;341:c3691

Methods

• n=11 921,meta-analysis of randomized placebo controlled trials. Patients were overwhelmingly female, typically osteoporotic seniors

• None of the trials included was designed (and powered) for cardiovascular outcomes (mainly fracture prevention studies).

• Intervention: minimum 500 mg of calcium daily without concurrent vitamin D

• Follow up: ≈ 4 years

• End points: MI, stroke, sudden death and their composite end point

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Results, myocardial infarctions (#)

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+27 %

Results, other CV endpoints

• No difference in strokes (1.20, 0.96 to 1.50, P=0.11)

• No difference in deaths (1.09, 0.96 to 1.23, P=0.18)

• No difference in composite end point (1.18, 1.00 to 1.39, P=0.057)

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Discussion

• Results of the meta-analysis are in contrast to observational studies, and raise concern about the safety of large scale use of calcium supplementation

• As the included studies were not designed to explore cardiovascular events, they are subject to bias

• Renal failure is common among elderly females, this meta-analysis and previous studies in renal failure throw doubt on the recommendation of routine calcium supplementation in elderly osteopenia and osteoporosis

• Mechanism behind the phenomenon is unknown, vascular calcification is suggested

• Authors conclude that reassessment of osteoporosis guidelines is warranted

6 www.pronutritionist.netBolland MJ et al. BMJ 2010;341:c3691

Discussion

• Results of the meta-analysis are in contrast to observational studies, and raise concern about the safety of large scale use of calcium supplementation

• As the included studies were not designed to explore cardiovascular events, they are subject to bias

• Renal failure is common among elderly females, this meta-analysis and previous studies in renal failure throw doubt on the recommendation of routine calcium supplementation in elderly osteopenia and osteoporosis

• Mechanism behind the phenomenon is unknown, vascular calcification is suggested

• Authors conclude that reassessment of osteoporosis guidelines is warranted

6 www.pronutritionist.netBolland MJ et al. BMJ 2010;341:c3691