Study under review: Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials
Approximately 54 million Americans have osteoporosis, a debilitating disease that causes a loss of bone density and mass and increases the risk of fracture. Guidelines from several organizations, including the U.S. National Osteoporosis Foundation, recommend dietary calcium intake of at least 700 milligrams per day for the prevention and treatment of osteoporosis for adults 50 years and older. The U.K. National Osteoporosis Guideline Group advocates the use of supplements to promote optimal bone health for people who do not eat the recommended intake of calcium through dietary sources.
However, there may be a downside to higher calcium intake. In the early 2010s, evidence emerged that calcium supplementation may cause an increased risk of cardiovascular disease (CVD), a group of disorders of the heart and blood vessels that includes coronary heart disease (CHD, a disease of blood vessels supplying the heart muscle) and cerebrovascular disease (a disease of the blood vessels supplying the brain).
However, later studies found that calcium supplementation did not increase the risk of CHD. Based on the results of a 2016 meta-analysis and systematic review showing no significant difference in risk of CVD events or mortality between calcium supplementation (with or without vitamin D) and placebo groups, the National Osteoporosis Foundation and the American Society for Preventive Cardiology issued a clinical guideline that there is moderate quality evidence that calcium intake, with or without vitamin D, from food or supplements does not increase the risk of CVD in healthy adults.
Given the conflicting findings from studies on this subject, the authors of the study under review aimed to investigate the associations between calcium supplementation and the risk of CVD through a comprehensive meta-analysis of placebo-controlled double-blind RCTs and subgroup analyses that addressed the controversial findings from previous studies. They also evaluated the differences in findings and study characteristics of previous systematic reviews and meta-analyses versus the current study.
Professional health organizations stress the importance of an adequate amount of calcium for the prevention and treatment of osteoporosis, and supplementation has been recommended if dietary intake is insufficient. There is conflicting evidence regarding the risk of CVD associated with calcium supplementation. The purpose of this study was to evaluate the association between calcium supplementation and the risk of CVD.
Other Articles in Issue #77 (March 2021)
Mini: Takeaways from the ISSN's position on caffeine and exercise performance
We break down some key takeaways from the International Society for Sports Nutrition's newly-updated position stance on caffeine's use in exercise performance.
D-creasing asthma symptoms with supplementation
Calcifediol is the form of vitamin D that's often checked in the blood to monitor vitamin D levels. This trial found that supplementing this form of vitamin D can improve asthma symptoms in people with vitamin D insufficiency.
Deep Dive: Micronutrients with micro-effects for preventing and treating acute respiratory infections
This meta-analysis found evidence that supplementing vitamins C and D may prevent the risk of acute respiratory infections, but only by a tiny amount. Zinc has a more sizable effect, but only once symptoms have set in.
The effects of full fasting vs. modified fasting on cognitive performance
How does full fasting impact mental functioning compared to very low-calorie intake over the course of a day? This study aimed to find out.
Nulls: November–December 2020
Highlights include omega-3's lack of impact on bipolar disorder, whether adding vitamin C to iron helps iron deficiency anemia outcomes, and more!
Battling exercise-induced muscle damage with omega-3s
This small study provides preliminary evidence that a high-dose mix of EPA and DHA may combat early post-exercise muscle soreness.
Deeper Dive: Shining a light on the effects of vitamin D on fall risk in older adults
This study suggests that higher vitamin D dosing doesn't prevent falls compared to lower dosing. Instead, it may cause more.