What the News Got Wrong About Calcium

Is Calcium Really Thumbs Down for Improved Bone Density?

 Calcium intake is taking a news beating with the study released September 29th by the British Journal of Medicine and leaning toward calcium supplementation not reducing the risk of bone fracture.   Before you start tossing out bottles of calcium and pouring milk down the drain, realize headlines are for shock value.  Believe me, it got my attention and warranted immediate research into the subject and published works.  We have come from the age of “milk does a body good” and taking care of osteoporosis with prescribed calcium supplements. How could in one instant all this come to a screeching halt?  I took the time to read the materials and want to inform you of some important details left out of the headlines.  

Calcium: Did You Catch That?

Calcium Stil Proven Effective for Bone Density. photoL/Getty Images

 The British Journal of Medicine conducted research on the benefits of increasing calcium coming from dietary sources or supplementation as a benefit to reduce fractures.  Did you catch that?  The studies are not referring to standard daily values of calcium, or saying calcium is not beneficial, but researching if additional calcium is required beyond a normal balanced diet.   This debate has been ongoing for years and still inconclusive evidence to support that more calcium is needed for improved bone density or to decrease fracture risk.  The research is impressive however with randomized controlled trials, double blind placebo, and cross referenced over 40 studies to support their conclusions.  Research comes with inconsistencies and stated within the study “an important limitation is the difficulty of identifying all cohort studies that reported relations between calcium intake and fracture risk.” 

Calcium Research Says

Calcium is a Mineral Linked to Strong Bones. Denise Bush E+/Getty Images

 Let’s take a look at some highpoints within the study and come to our own conclusions about calcium.  The strengths of the studies are randomized controlled trials, observational studies, and assessment of four fracture points including the hip, vertebral, and forearm.  The weakness of the research came from the referenced cohort studies and not performing a quality assessment of the studies but using the results anyway.  Other study weaknesses included short trial duration, using bone mineral density (BMD) as the endpoint instead of fracture, and limiting trial participants to healthy populations or those with risk of osteoporosis.  The research findings would be inconclusive based on not having a broader scope of people and more accurate endpoint.  Some of the findings revealed there is little evidence to support increased dietary calcium as a factor to decrease fracture risk, however supplementation showed inconsistent improvements.  The study presents pros and cons of calcium intake through dietary and supplemental sources.  For example and contradictory to the headlines, “small benefits might be useful at a population level if calcium supplements were used widely, well tolerated, and safe.” Concern for gastrointestinal upset and cardiovascular issues caused by increased calcium throughout the publication gave rise to the statement “because of the small benefits of use and unfavorable risk, calcium supplements should not be recommended for fracture prevention either at an individual or population level.” Further conclusions do reveal small improvements in bone mineral density (BMD) but since the margin is only 1-2%, the study supports “small effects on BMD are unlikely to translate into clinically meaningful reductions in fractures.”   I am sure more research and updates will be occurring, “future trials conducted should have a strong rationale as to why the results are likely to differ from the large body of existing trial evidence.”

A Better Headline

Calcium and Bone Density
Studies Still Show Calcium to Increase Bone Density. Henrik Sorensen Stone/Getty Images

 Thinking about the headline, it could have gone something like this: Are Small Bone Density Improvements worth the Calcium Supplement?  I also wonder when small improvements became insignificant.  Isn’t progress, regardless of how small, progress?  Rant over!


The British Journal of Medicine, Calcium supplements do not prevent fractures, Karl Michaëlsson, 9/29/15

The British Journal of Medicine, Research, Calcium intake and bone mineral density: systematic review and meta-analysis, Vicky Tai et al., 9/29/15

The British Journal of Medicine, Research, Calcium intake and risk of fracture: systematic review, Mark J Bolland et al., 9/29/15

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