A new scientific review challenges recent consumer concern by finding no credible evidence linking calcium supplements to increased risk of heart disease. The analysis, which examined the full body of scientific evidence on calcium supplementation and cardiovascular health, concluded that calcium remains both safe and essential when consumed within established intake levels, according to the Council for Responsible Nutrition (CRN) Foundation.
The CRN Foundation released the review as part of the fourth edition of Vitamin and Mineral Safety (VMS4), its initiative to provide “information and education about the beneficial, safe, and responsible use of dietary supplements and their ingredients as part of a healthy lifestyle.” The review affirms that supplemental calcium is not associated with a greater risk of cardiovascular disease.
“Consumers have heard for years that calcium supplements might harm heart health, but that narrative simply isn’t supported by the weight of the science,” said Andrea Wong, Ph.D., senior vice president and chief science officer at CRN.
“When you look at the body of evidence — including independent reviews and recent clinical trials — there is no credible link between calcium supplementation and cardiovascular risk in generally healthy individuals,” Wong said.
What role does calcium play in human health?
Calcium is an essential mineral widely regarded for its role in bone health. Its benefits extend beyond the skeleton, as it also affects blood pressure and cholesterol, both of which play roles in cardiovascular health.
While dairy products are the best known dietary sources of calcium, it also is present in nuts and seeds, fortified cereals and select green vegetables such as kale and broccoli. Calcium supplements frequently are formulated with vitamin D because it facilitates calcium absorption in the intestines.
Calcium often enters conversations about heart health because of vascular calcification, which increases blood vessel stiffness. Vitamin K, in particular K2, can regulate calcium mineralization by preventing arterial stiffening and bone loss.
Why have calcium supplements come under fire for increasing heart disease risk?
Calcium supplementation has come under question for a potential link to heart attacks and strokes largely out of secondary analyses of the Women’s Health Initiative (WHI), which was designed to better understand morbidity and mortality causes such as cardiovascular disease and bone fractures resulting from osteoporosis for postmenopausal women.
The study “had significant methodological limitations, including poor compliance tracking, confounding variables and lack of adjustment for known cardiovascular risk factors,” according to CRN.
One of the early analyses of the WHI data, published in 2011, stated “calcium supplements with or without vitamin D modestly increase the risk of cardiovascular events, especially myocardial infarction (heart attack).” A more recent analysis, published in 2024, suggested calcium supplementation increased cardiovascular disease by 6%.
Subsequent analyses have shown no impact of calcium supplementation on cardiovascular disease risk. One such analysis also factored in the use of hormone replacement therapy and suggested calcium supplementation mollified the increased stroke risk resulting from estrogen therapy.
Robust analyses find no risk
CRN is not the only organization to take up the mantle to clarify calcium’s link to heart health risks.
Subsequent, more robust analyses — including reexaminations of the WHI data — found no increased risk of heart attack, stroke or overall cardiovascular disease associated with calcium supplementation.
The European Food Safety Authorityhttps://efsa.onlinelibrary.wiley.com/doi/abs/10.2903/j.efsa.2012.2814 (EFSA) concluded that calcium intakes from diet and supplements up to 2,500 mg per day are safe, well-tolerated and not linked to increased risk of cardiovascular disease.
Additionally, the National Osteoporosis Foundation and the American Society for Preventive Cardiology adopted the position that sufficient evidence suggests calcium is not associated with risk of cardiovascular disease, independent of coadministration with vitamin D.
The bottom line: Calcium supplementation is safe
The CRN Foundation’s findings published in VMS4 support calcium supplementation up to 1,500 mg daily for adults, in line with global scientific consensus. CRN affirms the safety of calcium and its essential role in human health.
“Calcium plays a vital role in lifelong health, especially for bone strength and healthy aging,” Wong said.
“Consumers should feel confident meeting their calcium needs through diet and supplements without fear of harming their heart.”
