People who take calcium supplements are more likely to end up with calcium in their arteries. That is the conclusion from a study that took 10 years to complete (Journal of the American Heart Association, October 11, 2016).
The Multi-Ethnic Study of Atherosclerosis:
More than 5,000 people between 45 and 84 years old participated in the Multi-Ethnic Study of Atherosclerosis (MESA) over the course of 10 years. They filled out questionnaires about their dietary habits and supplement use. Coronary artery scans were performed to detect calcification. About half of the participants had a second scan at the end of the study.
More Calcium from the Diet, Less from Calcium Supplements:
The researchers found that those who got the most calcium had the cleanest arteries–unless it was coming from calcium supplements. In that case, they had the most calcification.
Calcium and Atherosclerosis:
Atherosclerosis is the medical term for hardened arteries. But, you may wonder, doesn’t that have to do with plaque in the arteries? Well, yes it does. Even though doctors have focused most sharply on cholesterol in arterial plaque, these lesions actually contain more calcium than cholesterol. It is the calcium that makes plaque-laden arteries “hard.”
When coronary arteries become calcified, people are more likely to develop heart disease. This study confirms the results of other research implicating calcium supplements in the development of hardened arteries. You can read what we wrote about some previous studies here and here. You may also want to read what else we have written about these findings from the MESA study.
Are Calcium Pills a Bad Idea?
Q. A friend I trust a lot says that any calcium supplementation is a bad idea. Contrary to expectation, it does not help build bone strength, and further it is not neutral: it can be bad for the heart. I have been taking calcium citrate, but I wonder if I should stop.
A. Calcium supplements have long been recommended for older women. The idea was that extra calcium could help strengthen bones, reduce the risk of fractures and possibly even have cardiovascular benefits.
Those assumptions are now controversial. There is some evidence to suggest that calcium supplements with vitamin D may increase the chance of earlier death in people with narrowed heart valves (Heart, May 25, 2022). Dietary calcium does not appear to pose a similar problem (JACC Advances, May 20, 2024).
People with diabetes who take calcium supplements are at risk for cardiovascular events and premature death, but not those whose glucose metabolism is normal (Diabetes Care, July 28, 2023). Unfortunately, data from the Women’s Health Initiative do not support calcium supplements with vitamin D to prevent fractures (JAMA, May 1, 2024).
Getting your calcium from food rather than supplements appears to be preferable. Good food sources include dairy products such as yogurt, cottage cheese, milk or mozzarella, canned salmon or sardines (with bones), tofu, soybeans or soy milk and dark green vegetables such as spinach, turnip greens, kale or bok choy.
What About Strong Bones?
Most of the people taking calcium supplements are doing so because they believe this will prevent bone loss and protect them from fracture. If only that were the case!
While a certain amount of calcium is essential so that young people can develop healthy bones and older people can maintain bone strength, it turns out that excess calcium from supplements is not associated with stronger bones that don’t break. A meta-analysis of 59 studies found that people taking calcium had very modest increases in bone mineral density, one way to measure bone strength (BMJ, Sept. 29, 2015). These gains did not last beyond a year or two, however. The researchers concluded: “for most individuals concerned about their bone density, increasing calcium intake is unlikely to be beneficial.”
The Take-Home Message:
The bottom line is complicated in theory, but (luckily) simpler in practice. To benefit both your heart and your bones, be sure to exercise every day. That gives your bones the resistance they need to stay strong, and it keeps your heart pumping and your blood vessels in shape.
Also, eat a varied diet with lots of vegetables and nuts, along with some dairy products if you tolerate them. You can get adequate calcium from almonds, beans, broccoli, bok choy, corn (not flour) tortillas, kale, mustard greens, spinach and Swiss chard. Tofu is a good source, too. If you are not vegetarian, add canned salmon and sardines, with the bones.
Learn More:
Either the Mediterranean diet or the DASH diet will make all this easier. If you’d like to learn more about these dietary approaches, you might want to read our book, The People’s Pharmacy Quick & Handy Home Remedy. It describes how to follow these diets. You might also want to listen to our Show 752: Bone Vitality, in which we discuss how to strengthen bones through diet rather than through calcium supplements.
Vitamin D is also needed for strong bones and healthy arteries. You can learn more about vitamin D supplements and the British recommendation that all adults take them here.
