Although best known for its protective role in bone health, calcium has other beneficial effects on human health. Studies suggest that adequate calcium intake may decrease the risk of gestational hypertension, colorectal cancer, and premenstrual syndrome. Over the past several decades, dietary and supplemental calcium intake of Canadians has increased, especially for women aged < 51 y. In more recent years, there is increasing evidence linking high calcium intake, mainly from supplements, to increased cardiovascular disease risk. Despite this evidence of adverse effects of calcium intake, there are no reports available to determine if there has been a shift in dietary or supplemental intakes of calcium in Canada. To ascertain whether there have been changes in dietary or total calcium intakes between 2004-2015 among Canadians aged > 1y, a study conducted by Hassan Vatanparast (University of Saskatchewan) and colleagues examined nationally representative nutrition data from 2 nationally representative surveys.
The study, which included 30,074,237 Canadians across 10 provinces, utilized dietary intake data collected with the use of two 24-h dietary recalls. Additional information on supplement intake was obtained, including frequency and amount of supplement intake. The National Cancer Institute method was used to estimate the usual intake of calcium and the prevalence of calcium inadequacy.
Study results, published in The Journal of Nutrition, suggest that the usual intake of calcium from food sources significantly decreased in calcium supplement nonusers, but not in calcium supplement users. The contribution of calcium from the Milk and Alternatives Food Group significantly decreased by 7.5% and 6.1% in calcium supplement users and nonusers, respectively.
The prevalence of calcium supplement use significantly decreased from 2004 to 2015 in the Canadian population, from 27.5% to 22.0%. During this time, the percentage contribution of calcium from supplemental sources significantly decreased among Canadians, especially women. The prevalence of calcium inadequacy increased from 58.0% to 68.0% in supplement nonusers; however, among users of calcium supplements, the prevalence of calcium inadequacy remained at nearly 31%.
According to senior author Hassan Vatanparast, “The decline in the overall prevalence of calcium supplement use may be attributable to publications linking calcium supplement use to increased risk of cardiovascular events.” Given that calcium intake from both food and supplemental sources decreased in the Canadian population over an 11-y period, the authors emphasize that policymakers should be encouraged to address this issue.
Reference Vatanparast H, Islam N, Patil RP, Shafiee M, Whiting SJ. Calcium Intake from Food and Supplemental Sources in the Canadian Population from 2004 to 2015. J Nutr. 2019 Dec 31 (Epub ahead of print; DOI: https://doi.org/10.1093/jn/nxz318).
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