Harvard Says Calcium Supplements Are Safe For Heart Health

 A study published in the British Medical Journal in 2010 caused considerable concern among doctors and postmenopausal women by saying that taking calcium supplements could increase arterial plaque and the risk of heart attacks.  Even though numerous highly respected calcium researchers dismissed the study, it caused considerable confusion among medical professionals, with some doctors telling postmenopausal women to quit taking calcium supplements.

 A new study of 1,278 senior men and women published in the American Journal of Clinical Nutrition that used advanced medical technology found no link between calcium supplements and increased cardiovascular risk. In fact, the study found what appeared to be a slightly reduced risk of coronary artery calcification with increasing total calcium intake.

 Study leader Elizabeth Samelson of Harvard and her team reported, "Our prospective study in a large, community-based population of women and men evaluated the relation between calcium intake, with an upper range as high as 3,000 mg a day, on a specific measure of the presence and severity of coronary atherosclerosis (i.e., coronary artery calcification), which is an independent predictor of cardiovascular events."

 "We used state-of-the-art CT measures of coronary artery calcification, and we were able to take into account important factors in a study of calcium intake and vascular calcification such as vitamin D intake, prevalent coronary artery disease, and kidney function.

 "Our results do not support a significant detrimental effect of calcium intake on coronary artery calcification.

 Calcium supplementation is an important preventive measure that protects bone density and reduces the risk of bone fracture for seniors.

 The North American Menopause Society recommends that women under 50 years of age take at least 1,000 mg of supplemental calcium per day, while they say that women 50 and over should take at least 1,200 mg of supplemental calcium per day.  In fact, it's worth considering taking more than 1,200 mg of supplemental calcium per day. Dr. Robert Heaney, who has published over 200 calcium studies since 1958 said, "Supplemented intakes of 1,300 to 1,700 mg per day have been shown to arrest age-related bone loss and to reduce fracture risk in people 65 and older." 3 He also said, "Supplemental [calcium] intakes of 2,400 mg per day can restore the setting of the parathyroid glands to young adult values." Improving parathyroid function to young adult values can reduce the loss of calcium from bone and bone loss, which reduces the risk of fractures.


The National Academy of Sciences Institute of Medicine says that long-term calcium supplementation for healthy adults is safe at 2,500 mg per day. They further state that the Lowest Observed Adverse Effect Level (LOAEL) for calcium is 5,000 mg a day. The LOAEL is a dose where toxicity might occur for some people when taken over a period of time.



1. Bolland MJ, et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ. 2010 Jul 29;341:c3691. Doi: 10.1136/bmj.c3691


E.J. Samelson, et al. Calcium intake is not associated with increased coronary artery calcification: the Framingham Study. Am J Clin NutrDecember 2012, Volume 96, Pages 1274-1280, doi:10.3945/ajcn.112.044230

Heaney RP. Calcium needs of the elderly to reduce fracture risk. J Am Coll Nutr 2001 Apr;20(2 Suppl):192S-197S.


Michael Mooney
Director of Research and Education