Calcium Affects More Than Just Bones

Posted by Andrea Hacker MS, RD on March 18, 2013

The Starting Line: 

Is calcium good for your bones, but bad for your heart?


Calcium is the most abundant mineral in our bodies, and it is 99% stored in our bones. When we do not get enough calcium through diet, the body will take it from our bones to maintain necessary blood calcium levels. Over time, this loss of calcium from the bones can result in low bone density. Peak bone mass is reached by 30 years of age. Before this age, a good goal is to build the strongest skeleton possible, and continue to maintain it after age 30. Getting adequate amounts of calcium through diet and/or supplements is essential for bone health.

Women over 50 are especially at risk for low bone density. This is because during menopause there is an average loss of 5-15% of bone mass. Statistically speaking, 50% of all women and 25% of all men will suffer a fracture after age 50. Risk factors include gender, age, previous fractures, a first degree relative with a history of fracture, extended use of corticosteroids, a body weight less than 127 pounds, and currently smoking.

In June 2012, a German research study reported that taking calcium supplements increased the risk of heart attack. The study elaborated that this increased risk did not occur if the extra calcium came from food sources. In fact, the researchers reported that individuals consuming 800mg of calcium per day from food sources had a 30% decrease in heart attack risk, while individuals taking calcium supplements had an increased risk of heart attacks. This effect was especially strong if the majority of their calcium came from supplements and not food.

It is not yet understood why calcium supplements might increase the risk of heart attacks. One hypothesis is that if someone is taking too much calcium at a time, it results in increased amount of calcium in the blood which can lead to hardening of the arteries and plaque build up.

As a runner, it is important to consume a healthy diet with enough calcium and vitamin D to maximize your bone health. Calcium-rich foods are also generally good sources of protein, potassium, B vitamins and other nutrients that are integral to health. As with anything, too much of a nutrient may change it from being beneficial to harmful.


Here are some basic facts for planning how your calcium input fits into your diet, from


Dietary recommendations for all adult men and women under 50 = 1000 mg/d

Dietary recommendations women over 50 = 1200 mg/d


Good dietary sources of calcium

-1 cup milk, yogurt, = 300mg

-1 oz of cheese = 150mg

-½ cup tofu = 150 mg

-fortified foods such as orange juice, soy milk, and energy bars have ~300 mg per serving.


Find out how much calcium you are getting in your diet at


The Finish Line:

Aim for 1000 mg of calcium each day in your diet and try to limit the amount of calcium supplements you take. This will maximize your bone health and limit your risk of heart attacks.



1. Li K, Kaaks R, Linseisen J, Rohrmann S.Associations of dietary calcium intake and calcium supplementation with myocardial infarctionand stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition study (EPIC-Heidelberg). 2012 Jun;98(12):920-5. doi: 10.1136/heartjnl-2011-301345.

Photo credit: Kyle May via photopin cc

 *Note: This general information is not intended to be a substitute for medical treatment or advice. Always consult a professional before making changes to your health and wellness practices. 

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