Calcium supplements may be associated with increased risk of heart attack.
Many people, especially those over age 50, take calcium supplements to prevent or treat osteoporosis. Recently, a large study raised concerns that healthy older women who take calcium supplements might be at increased risk for heart attacks. Investigators used a technique called meta-analysis, in which the results of a number of studies are combined, to examine the possible relation between calcium supplements and heart attacks.
The researchers used data from 15 studies in which one group received calcium supplements and one group did not. Use of calcium supplements was associated with a 30 percent increased risk of heart attack, regardless of gender or the amount of the calcium supplement.
In people with dietary calcium intakes of less than 800 milligrams per day, calcium supplements were not associated with an increased risk of heart attack. In contrast, those with dietary calcium intakes above 800 milligrams were at a higher risk of heart attack.
Studies where participants took both calcium and vitamin D and were compared to participants not receiving calcium or vitamin D were not included in this analysis. Supplements that combine calcium and vitamin D may not have the same effect as supplements that only contain calcium since vitamin D supplementation has been associated with a reduced mortality.
The researchers conclude, "Given the modest benefits of calcium supplements on bone density and fracture prevention, a reassessment of the role of calcium supplements in the management of osteoporosis is warranted."
For those vegans and vegetarians with low dietary calcium intakes, calcium supplements appear to reduce the risk of fracture (<www.vrg.org/journal/vj2007issue4/ vj2007issue4.pdf>) and should probably be used if dietary calcium is not adequate. For those whose diets are adequate in calcium, additional supplemental calcium may not be advantageous.
Bolland MJ, Avenell A, Baron JA, et al. 2010. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis.
BMJ [Epub ahead of print].
By Reed Mangels, PhD, RD, FADA
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|Title Annotation:||SCientific Update: A Review of Recent Scientific Papers Related to Vegetarianism|
|Date:||Apr 1, 2011|
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