Calcium Intake and Cardiovascular Disease Risk: An Updated Systematic Review and Meta-analysis

Compare to these conclusions in another research;
High total calcium intake was associated with a decreased risk of incident atherosclerosis over long‐term follow‐up, particularly if achieved without supplement use. However, calcium supplement use may increase the risk for incident CAC.
http://annals.org/aim/article/2571713/calcium-intake-cardiovascular-disease-risk-updated-systematic-review-meta-analysis

Mei Chung, MPH, PhD; Alice M. Tang, SCM, PhD; Zhuxuan Fu, MPH; Ding Ding Wang, MPH; Sydne Jennifer Newberry, MS, PhD

Article, Author, and Disclosure Information

PDF

Citations

Permissions

Published: Ann Intern Med. 2016.
DOI: 10.7326/M16-1165

©

2016 American College of Physicians

0 Views
0 Citations

FULL ARTICLE
• Abstract
• Methods
• Results
• Discussion
• Appendix: Technical Details
• References
• Figures
• Tables
• Supplements
• Comments

• Twitter Link
• Facebook Link
• Email Link

More

Abstract

Background:Conflicting evidence exists regarding potential cardiovascular risks associated with high levels of calcium intake.

Purpose:To update and reanalyze 2 systematic reviews to examine the effects of calcium intake on cardiovascular disease (CVD) among generally healthy adults.

Data Sources:MEDLINE; Cochrane Central Register of Controlled Trials; Scopus, including EMBASE; and previous evidence reports from English-language publications from 1966 to July 2016.

Study Selection:Randomized trials and prospective cohort and nested case–control studies with data on dietary or supplemental intake of calcium, with or without vitamin D, and cardiovascular outcomes.

Data Extraction:Study characteristics and results extracted by 1 reviewer were confirmed by a second reviewer. Two raters independently assessed risk of bias.

Data Synthesis:Overall risk of bias was low for the 4 randomized trials (in 10 publications) and moderate for the 27 observational studies included. The trials did not find statistically significant differences in risk for CVD events or mortality between groups receiving supplements of calcium or calcium plus vitamin D and those receiving placebo. Cohort studies showed no consistent dose–response relationships between total, dietary, or supplemental calcium intake levels and cardiovascular mortality and highly inconsistent dose–response relationships between calcium intake and risks for total stroke or stroke mortality.

Limitations:CVD disease outcomes were secondary end points in all trials. Dose–response metaregression analysis of cohort studies was limited by potential confounding, ecological bias, and imprecise measures of calcium exposures. Data were scarce regarding very high calcium intake—that is, beyond recommended tolerable upper intake levels.

Conclusion:Calcium intake within tolerable upper intake levels (2000 to 2500 mg/d) is not associated with CVD risk in generally healthy adults.

Primary Funding Source:National Osteoporosis Foundation.

Calcium is a nutrient essential for maintaining bone health. A small proportion of total body calcium (less than 1%) also regulates vascular contraction and vasodilation, muscle function, nerve transmission, intracellular signaling, and hormonal secretion. Vitamin D promotes calcium absorption in the gut and maintains adequate serum calcium and phosphate concentrations, enabling normal bone mineralization and preventing hypocalcemic tetany (1).

Although adequate calcium and vitamin D intake is critical for maintaining bone health, the role of calcium and vitamin D supplementation in older adults is unclear. Some systematic reviews showed that combined calcium and vitamin D supplementation reduced the risk for fractures in older adults (2, 3), whereas more recent systematic reviews reported inconsistent effects for fractures across randomized, controlled trials (4, 5). Experts have raised concerns about a potential effect of a high intake of calcium (with or without vitamin D) from foods and supplements on cardiovascular disease (CVD) outcomes (6–8). A meta-analysis of both study- and patient-level data from randomized trials showed that calcium with or without vitamin D supplementation increased the risk for myocardial infarction (pooled relative risk, 1.24 [95% CI, 1.07 to 1.45]) and stroke (pooled relative risk, 1.15 [CI, 1.00 to 1.32]) (9, 10). However, a more recent meta-analysis showed that calcium with or without vitamin D supplementation had no statistically significant effects on coronary heart disease events (pooled relative risk, 1.02 [CI, 0.96 to 1.09]) or mortality (pooled relative risk, 1.04 [CI, 0.88 to 1.21]) (11). Many researchers have questioned the strength of the body of evidence linking supplemental calcium intake with CVD risk, noting that cardiovascular outcomes have not been the primary end point of any trial investigating calcium or calcium and vitamin D supplementation to date (12, 13).

To inform a joint position statement from the National Osteoporosis Foundation (NOF) and American Society for Preventive Cardiology, NOF commissioned a focused update and reanalysis of 2 broader evidence reports examining the effects of calcium and vitamin D on a wide range of clinical and intermediate outcomes (5, 14). This update addresses the effects of calcium intake (from dietary or supplemental sources), alone or in combination with vitamin D, on CVD risk in generally healthy adults.

More at link.