Are Calcium Supplements Harming Your Heart?
We’re often told to get enough calcium to help build and maintain strong bones, but if you take calcium supplements, could they be harming your heart? The results of a new study in the journal Heart indicate you should take a second look at your calcium supplements and the calcium in your diet.
Calcium has an impact on heart health
We live in a pop-a-pill world. Rather than turn to whole, natural foods to get the nutrients the body needs, we often choose to take nutritional supplements.
Calcium is a popular supplement and a critical mineral for bone health and other important biochemical processes throughout the entire life cycle. However, the push to take calcium supplements is especially strong for menopausal and postmenopausal women and the elderly, all of whom have a greater risk of developing osteoporosis and experiencing falls and fractures.
There is also evidence that calcium supplements might increase the risk of experiencing a heart attack. This finding comes from an evaluation of nearly 24,000 individuals who participated in one arm of the European Prospective Investigation into Cancer and Nutrition (EPIC) study.
All the study participants were between the ages of 35 and 64 when they enrolled in the study in 1994 to 1998. Dietary habits were identified using food frequency questionnaires, and all the subjects revealed their use of supplements.
During an 11-year follow-up, a total of 354 heart attacks, 260 strokes, and 267 deaths were documented. When these incidents were evaluated in light of the individuals’ diet, the following was revealed:
- Individuals who took calcium supplements regularly were 86% more likely to experience a heart attack than study participants who did not take any supplements
- Individuals who used calcium supplements as the only nutritional supplement were more than twice as likely to have a heart attack as study participants who didn’t use any type of supplements
- Participants whose diets included moderate calcium intake (820 mg daily) from all food and supplements had a 31% lower risk of having a heart attack than subjects in the bottom 25% of calcium intake.
- Participants who consumed more than 1,100 mg daily of calcium did not have a significantly lower risk of heart attack
- The authors found no evidence that any amount of calcium helped protect against stroke or increased the risk of stroke
The two faces of calcium supplements
Studies of the risks and benefits of taking calcium supplements present an array of food for thought. Before the current study, research conducted at the University of Auckland and published in 2010 noted an increased risk of heart attack associated with calcium supplementation.
A 2011 study published in the American Journal of Clinical Nutrition discussed the impact of calcium and vitamin D supplements on risks of cancer, fracture, and death in participants of the Women’s Health Initiative (WHI) CaD Study who were not taking these supplements before they entered the seven-year trial. The investigators found that calcium (1,000 mg daily) and vitamin D (400 IU daily) decreased the risk of total, breast, and colorectal cancers but had no effect on the risk of fractures or death from any cause.
Another 2011 report in the American Journal of Clinical Nutrition noted an increased risk of kidney stones associated with long-term calcium and vitamin D supplement use among postmenopausal women. Calcium supplements have also been named as possibly helping with weight loss.
Calcium clearly offers both benefits and risks, and individuals should discuss their calcium requirements with a knowledgeable professional. Part of that discussion may include the conclusion drawn by the authors of the Heart study, which is that “increasing calcium intake from diet might not confer significant cardiovascular benefits, while calcium supplements, which might raise [heart attack] risk, should be taken with caution.”
Bolland MJ et al. Effect of calcium supplements on risk of myocardial infarction and cardiovascular events: meta-analysis. BMJ 2010 Jul 29; 341:c3691
Bolland MJ et al. Calcium and vitamin D supplements and health outcomes: a reanalysis of the Women’s Health Initiative (WHI) limited-access data set. Am J Clin Nutr 2011 Oct; 94(4): 1144-49
Li K et al. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition Study (EPIC-Heidelberg). Heart 2012. DOI:10.1136/heartjnl-2011-301345