Increased calcium intakes seem not to elevate risk for cardiovascular disease

According to a large long-term study, calcium supplement intakes do not increase the risk for women to develop coronary heart disease or stroke.

The prospective cohort study investigated a potential link between the regular use of calcium supplements and the incident of cardiovascular disease (coronary heart disease and stroke) in 74,245 women (aged 30 to 55 years) over a period of 24 years (1). The study results showed that – after adjustment for age, body mass index, dietary calcium intake, vitamin D intake, and other cardiovascular disease (CVD) risk factors – the relative risk of developing CVD for women taking more than a daily 1,000 mg calcium from supplements compared with the risk of none-users was not significant. Instead, a possible association between calcium supplement use and a decreased CHD risk was observed.

The researchers commented that previous studies on the association between calcium supplements and CVD risk have reported conflicting results. While some long-term studies showed no increased CVD risk linked to calcium intakes (2, 3), other shorter-term studies reported an elevated risk (4–6). To date, no randomized controlled trial has tested the effect of calcium supplementation on CVD as its primary endpoint. Calcium supplements may improve lipid profiles (7) and lower blood pressure (8). On the other hand, they could hypothetically increase CVD risk by elevating serum calcium, which could promote vascular calcification and CVD events (9).

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3. Xiao Q. et al. Dietary and supplemental calcium intake and cardiovascular disease mortality: the National Institutes of Health-AARP Diet and Health Study. JAMA Intern Med. 2013; 1–8.
   
4. Pentti K. et al. Use of calcium supplements and the risk of coronary heart disease in 52–62-year-old women: the Kuopio Osteoporosis Risk Factor and Prevention Study. Maturitas. 2009; 63:73–78.
   
5. Li K. et al. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study (EPIC-Heidelberg). Heart. 2012; 98:920–925.
   
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7. Reid I. et al. Effects of calcium supplementation on serum lipid concentrations in normal older women: a randomized controlled trial. Am J Med. 2002; 112:343–347.
   
8. Griffith L. et al. The influence of dietary and non-dietary calcium supplementation on blood pressure: an updated meta-analysis of randomized controlled trials. Am J Hypertens. 1999; 12(1 Pt 1):84–92.
   
9. Foley R. N. et al. Calcium-phosphate levels and cardiovascular disease in community-dwelling adults: the Atherosclerosis Risk in Communities (ARIC) Study. Am Heart J. 2008; 156:556–563.