Features January 2014 Issue

Clarifying the Controversy Behind Calcium Supplements

As research connects calcium supplements to heart disease, experts enforce diet as the best way to deliver the element needed for bone health.

The idea of popping a calcium supplement to ensure strong bones seems simple. While many people rely on the approach of one calcium pill to prevent osteoporosis, recent studies have questioned the safety of these dietary supplements.
Interpreting troublesome findings

Calcium supplements are the second-most common supplements taken by adults in the United States.

The most concerning reports focus on inconsistent findings that calcium supplements may increase the risk of cardiovascular disease. To clarify the potential threat to heart health, a recent assessment of the scientific literature advises patients and healthcare practitioners to focus on a high-calcium diet rather than supplements to achieve proper calcium intake.

Yet, if it’s not possible to receive adequate amounts of calcium from diet, the use of calcium supplements is most likely safe and not associated with cardiovascular outcomes, states the perspective piece published in the New England Journal of Medicine (Oct. 17).
Calcium is one of the building blocks for good bone health, but understanding how much your body needs and the best way to get this essential element is important to gaining the benefits, according to Cleveland Clinic’s Director of Regional Rheumatology Rochelle Rosian, MD.
“It’s important to get adequate amounts of calcium daily, but trying to increase the level through extra supplements isn’t necessarily beneficial for bone health,” she says.

Understanding the potential risks
Word of calcium’s possible negative impact came in 2010 when a study published in the British Medical Journal concluded that calcium supplements “are associated with an increased risk of myocardial infarction (heart attack).” Additional findings from a 2013 JAMA Internal Medicine study concluded, “high intake of supplemental calcium is associated with an excess risk of CVD (cardiovascular disease) death in men but not in women.”
“There has been a lot of confusion about the safety of calcium supplements, but it’s important to point out that several other studies have shown no relationship between the use of the supplements and cardiovascular events,” explains Dr. Rosian. “Essentially, calcium through the diet is preferred, but supplements are a safe way of incorporating the element.”

Telling numbers
Data from the National Health and Nutrition Examination Survey found that nearly one-half of adults in the United States use dietary supplements, and products that contain calcium are the second-most common supplements overall. However, a meta-analysis of 29 studies found that calcium use alone was associated with a nonsignificant reduction in the risk of bone fracture.


Patients who have low calcium intake, less than 600 mg per day, may have less bone loss and fewer fractures by taking supplements. “The best way to ensure overall bone health is by getting both calcium and vitamin D in the diet,” Dr. Rosian says. “The two nutrients work together to help prevent the effects of osteoporosis.”
The Institute of Medicine recommends getting 600 international units (IU) of vitamin D a day for adults ages 19 to 70, and 800 IU for those older than 70.
For calcium, the daily recommendations vary by age and gender: Adult men ages 51 to 70 need 1,000 mg, and adult women in the same age range require 1,200 mg.
It’s important to note that some patients may require much higher doses, especially if they are vitamin D deficient or have gastrointestinal disease that reduces the amount of vitamin D absorbed, explains Dr. Rosian.

Focus on delivery
Whether calcium is received through diet or a supplement pill, it’s how the essential element is delivered to the body that makes a difference, explains Dr. Rosian. “The body only absorbs 400 to 500 mg of calcium at one time,” she says. “Taking a huge supplement that consists of 1,200 mg at once is not helpful.”
A balanced diet aids calcium absorption, while high levels of protein and sodium in the diet are thought to increase calcium excretion through the kidneys.
The use of proton pump inhibitors (such as Prilosec® and Prevacid®) has been associated with a small increase in fracture risk; the mechanism may be decreased absorption of calcium, which requires stomach acid for optimum uptake.

Calcium inhibitors
“Caffeine and alcohol prevent calcium absorption, while juice fortified with calcium, such as orange juice, is one way to increase your calcium intake without taking a supplement,” Dr. Rosian says.

If calcium levels aren’t being met through diet, supplements can be taken in 400 mg dosages, three to four times a day, she explains.
“Overall, it’s important to build a good foundation for bone health through a diet that’s rich in calcium and vitamin D,” she says.
“Just like a job site, you can hire more workers but if you don’t have the fundamental building blocks, the extra workers won’t be helpful.”