There’s no denying that calcium plays an essential role in a variety of bodily functions – muscle contractions, nerve conduction, turning on certain hormones – but we know it best as a mineral that promotes bone health. In fact, 99% of the calcium in your body lies in your bones and teeth.
For years, we’ve heard about how important it is to get the recommended amount of calcium daily, 1200 milligrams each day for bone health for women over 50 and 1,000 milligrams for ladies under 50. As a result, many women turned to calcium supplements as a way to preserve bone health – but is this wise?
Although the idea of supplementing with calcium for bone health sounds like a smart move, recent research raises questions as to how strong of a role calcium really plays in bone health, especially in women over the age of 50. Is it time to rethink the role calcium plays in bone density and fracture prevention?
Calcium Supplements and Dietary Calcium for Bone Health
A large meta-analysis analyzed 110 studies looking at the effects of calcium supplements AND dietary calcium on bone density. The conclusion? When participants took calcium supplements OR increased their intake of calcium through diet, it only led to small increases in bone density. These increases were so small that they would be unlikely to reduce the risk of bone fractures. Even in a study where participants took calcium supplements and vitamin D, the risk of hip fracture wasn’t significantly reduced.
Of course, you might consider taking a calcium supplement as an “insurance policy” to be sure you meet your body’s baseline need for calcium. Unfortunately, calcium supplements are not entirely free of risks or side effects. Calcium supplements, but not dietary calcium, are linked with a higher risk for kidney stones, and calcium supplements cause constipation in a significant number of people.
Even more concerning were studies published a few years ago showing a higher risk for heart attacks among men taking calcium supplements. More reassuring is a study published in the Journal of Clinical Endocrinology and Metabolism in 2013 that showed a LOWER risk of heart disease among men and women who consumed more calcium from diet or supplements.
Another Canadian study found that women who took calcium supplements containing no more than 1,000 milligrams of calcium had a 22% lower risk of death over a 10-year period compared to those who didn’t take a supplement. Beyond 1,000 milligrams daily, there was no reduction in death.
Calcium and Vitamin D for Bone Health
Interestingly, higher doses of calcium (over 1,000 milligrams per day) may interfere with the bone-protective effects of vitamin D, another vitamin important for bone health. According to Dr. Fuhrman, director of functional medicine at the Cleveland Clinic, high quantities of calcium can block the activity of vitamin D and lead to a loss of bone density.
Here’s another fact about bone health you may not be aware of. A diet high in sodium is also a risk factor for bone loss. When you take in too much dietary sodium, you excrete more calcium into your urine. In a study carried out in Japan, researchers found women who ate a high-sodium diet had 4-times the risk of developing a fracture anywhere other than their spine.
The Best Approach to Getting Enough Calcium
As you can see, the link between bone health and calcium may not be as solid as previously thought. Plus, keeping your bones strong and healthy involves more than just calcium – you need high-impact physical activity, vitamin D, vitamin K, and magnesium, all of which play an important role in keeping your bones healthy. In other words, if you’re counting on a diet high in calcium alone to protect your bones, you may be disappointed.
Depending upon the type of diet you eat, you might think getting enough calcium is challenging, but dairy foods aren’t the only source of this mineral. If you don’t eat dairy foods, you can still get calcium from green, leafy vegetables, soy-based foods, and calcium-fortified beverages like orange juice. Did you know two cups of broccoli has 150 milligrams of calcium? Green, leafy vegetables are another abundant source of calcium. Tofu, too, can be a phenomenal calcium source, as long as it’s made with calcium sulfate. It should say so on the package.
Is dairy really necessary? As Dr. Fuhrman points out, osteoporosis and fractures are actually more common in cultures that consume lots of dairy. One reason may be that dairy products are acidic. Your body has to buffer the excess acidity and it does so by drawing calcium from bones. In contrast, vegetables are alkaline, which is more favorable for bone health.
The point is, with a little planning, you can get enough calcium in your diet without taking calcium supplements. If you have a family history of kidney stones, you should avoid taking calcium supplements anyway. It’s also not completely clear whether getting large quantities of calcium, greater than 1,000 to 1,200 milligrams daily is healthy for your heart and blood vessels.
The most recent research shows calcium may LOWER the risk of heart disease, but this conflicts with some earlier studies suggesting getting high doses of calcium may actually increase heart disease risk. Don’t you love it when research is conflicting? Most of the evidence suggests that calcium is probably NOT strongly linked with heart disease.
So, what should you do? Aim for a moderate amount of calcium that you get through diet rather than supplements. Unless you eat a low-calcium diet, you probably don’t need a calcium supplement and should also focus on getting enough magnesium and vitamin D. If you HAVE osteoporosis already, talk to your doctor about whether a calcium supplement is right for you.
BMJ 2015; 351 doi: http://dx.doi.org/10.1136/bmj.h4183 (Published 29 September 2015)
Consumer Lab. “Calcium Supplements Reviewed by Consumer Lab”
J Clin Endocrinol Metab. 2013 Jul;98(7):3010-8. doi: 10.1210/jc.2013-1516. Epub 2013 May 23.
Dr. Fuhrman. “Calcium, Vitamin D, and Osteoporosis”
J Bone Miner Res. 2015 Jan;30(1):165-75. doi: 10.1002/jbmr.2311.
Science Daily. “Excessive salt consumption appears to be bad for your bones”
WebMD. “Calcium Supplements Tied to Kidney Stone Risk”
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