Analysis finds no safety concerns for calcium supplements and heart health

There are “no compelling associations” between calcium supplementat use and increased risks of cardiovascular disease (CVD) events, says a new study.

Data from the 6,236 men and women participating in the diverse Multi-Ethnic Study of Atherosclerosis (MESA) cohort failed to identify any impact on calcium on heart attack of CVD event risk, according to findings published in Nutrition, Metabolism and Cardiovascular Diseases.

The results support the safety profile of the mineral, which has been questioned by some members of the academic community.

Bone health and heart health

Osteoporosis has been described as a silent killer, and recent data from the National Osteoporosis Foundation showed that approximately 9 million American adults currently have osteoporosis and another 48 million have low bone mass, placing them at increased risk.

An economic report from Frost & Sullivan and commissioned by the Council for Responsible Nutrition (CRN) recently found that supplements of calcium plus vitamin D for all US women with osteoporosis could provide healthcare cost savings of $1.08 billion per year.

Despite the clear benefits of calcium (and vitamin D) for bone health, papers published in journals such as JAMAHeart, and the British Medical Journal found significant adverse cardiovascular effects related to excessive calcium intake in different populations, leading to concerns, and even condemnation of calcium supplements by some.

The plaques that form in diseased arteries are composed mostly of calcium, and some researchers have postulated that this is directly related to the rapid spiking of blood calcium levels following ingestion of the supplement.

Sales slump

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© iStock / sasimoto (SASIWIMOL K.)

The literature, however, is contradictory, with data published in the American Journal of Clinical Nutrition concluding that current evidence does not support the notion that calcium supplements increase the risk of heart disease in elderly women. In addition, a meta-analysis published in 2015 came to the same conclusions. Writing in the Journal of Bone and Mineral Research, the authors concluded: “The findings that calcium supplementation with or without vitamin D in elderly women did not increase coronary heart disease or all-cause mortality or the separate secondary outcomes of myocardial infarction, angina and acute coronary syndrome, and chronic coronary heart disease verified by clinical review, hospital record, or death certificate are reassuring.”

Sales of calcium supplements have been affected by the controversy. According to data from Euromonitor, US consumers spent $914.3 million on calcium supplements, a 6% decrease from $973.7 million in 2014. The same data set is grave in its 2016 predictions, forecasting an additional 5% decrease to $864.9 million.

Study details

Researchers led by Dr Laura Raffield from the University of North Carolina at Chapel Hill analyzed data from over 6,000 men and women aged between 45 and 84 based at six different sites across the US.

Dr Raffield and her co-workers recorded 208 heart attacks and 641 CVD events over 10.3 years of studying the cohort, but no association between calcium intake of supplement use and incident CVD events were observed.

“Our negative results are consistent with the lack of a clear mechanism for why calcium supplementation would increase CVD risk,” wrote the researchers. “Vascular calcification, a measure of subclinical CVD risk, has been suggested as a potential mediator of the negative CVD impacts of calcium supplementation. However, studies have consistently found no association between calcium supplement use and vascular calcification.”

Source: Nutrition, Metabolism and Cardiovascular Diseases

Published online ahead of print, doi: 10.1016/j.numecd.2016.07.007

“The Association of Calcium Supplementation and Incident Cardiovascular Events in the Multi-Ethnic Study of Atherosclerosis (MESA)”

Authors: L.M. Raffield