Study Title:

Calcium Intake and Mortality in Women

Study Abstract

Context:Calcium and vitamin D are recommended for bone health, but there are concerns about adverse risks. Some clinical studies suggest that calcium intake may be cardioprotective, whereas others report increased risk associated with calcium supplements. Both low and high serum levels of 25-hydroxyvitamin D have been associated with increased mortality.

Objective:The purpose of this study was to determine the association between total calcium and vitamin D intake and mortality and heterogeneity by source of intake.Design:The Canadian Multicentre Osteoporosis Study cohort is a population-based longitudinal cohort with a 10-year follow-up (1995-2007).

Setting:This study included randomly selected community-dwelling men and women.

Participants:A total of 9033 participants with nonmissing calcium and vitamin D intake data and follow-up were studied.

Exposure:Total calcium intake (dairy, nondairy food, and supplements) and total vitamin D intake (milk, yogurt, and supplements) were recorded.

Outcome:The outcome variable was all-cause mortality.

Results:There were 1160 deaths during the 10-year period. For women only, we found a possible benefit of higher total calcium intake, with a hazard ratio of 0.95 (95% confidence interval, 0.89-1.01) per 500-mg increase in daily calcium intake and no evidence of heterogeneity by source; use of calcium supplements was also associated with reduced mortality, with hazard ratio of 0.78 (95% confidence interval, 0.66-0.92) for users vs nonusers with statistically significant reductions remaining among those with doses up to 1000 mg/d. These associations were not modified by levels of concurrent vitamin D intake. No definitive associations were found among men.

Conclusions:Calcium supplements, up to 1000 mg/d, and increased dietary intake of calcium may be associated with reduced risk of mortality in women. We found no evidence of mortality benefit or harm associated with vitamin D intake.

From press release:

Taking a calcium supplement of up to 1,000 mg per day can help women live longer, according to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

Calcium, an essential nutrient for bone health, is commonly found in dairy products as well as vitamins. Although calcium is an essential nutrient for bone health, past studies have linked calcium supplements to heart disease risk. Researchers analyzing data from the large-scale Canadian Multicentre Osteoporosis Study (CaMos) sought to clarify this issue and found moderate doses of calcium supplements had a beneficial effect in women.

"Our study found daily use of calcium supplements was associated with a lower risk of death among women," said the study's lead author, David Goltzman, MD, of McGill University in Montreal, Canada. "The benefit was seen for women who took doses of up to 1,000 mg per day, regardless of whether the supplement contained vitamin D."

The longitudinal cohort study monitored the health of 9,033 Canadians between 1995 and 2007. During that period, 1,160 participants died. Although the data showed women who took calcium supplements had a lower mortality risk, there was no statistical benefit for men. The study found no conclusive evidence that vitamin D had an impact on mortality.

"Higher amounts of calcium were potentially linked to longer lifespans in women, regardless of the source of the calcium," Goltzman said. "That is, the same benefits were seen when the calcium came from dairy foods, non-dairy foods or supplements."

Study Information

Langsetmo L, Berger C, Kreiger N, Kovacs CS, Hanley DA, Jamal SA, Whiting SJ, Genest J, Morin SN, Hodsman A, Prior JC, Lentle B, Patel MS, Brown JP, Anastasiades T, Towheed T, Josse RG, Papaioannou A, Adachi JD, Leslie WD, Davison KS, Goltzman D; the CaMos
Calcium and Vitamin D Intake and Mortality: Results from the Canadian Multicentre Osteoporosis Study (CaMos)
J Clin Endocrinol Metab.
2013 May
CaMos National Coordinating Centre, McGill University, Montreal, Quebec H3A 1A1, Canada.

Full Study