Why calcium supplements don’t work

Calcium supplement

If you take a calcium supplement you may want to consider stop taking it as a new study just found that increasing calcium intake is unlikely to boost bone health or prevent fractures. Even if you try to increase your calcium intake through your diet this may not make a difference as concluded by the two studies published in the British Medical Journal. Surprised? I am not actually and I will tell you why in a second.

The first study found that increasing calcium intake from dietary sources or by taking supplements produces small (1-2%) increases in bone mineral density, which “are unlikely to lead to a clinically meaningful reduction in risk of fracture.” (1) For this reason calcium supplements should not be recommended for fracture prevention.

The second study found that dietary calcium intake is not associated with risk of fracture, and ‘there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures’. (1)

Many people are taking calcium supplements in order to treat osteoporosis or to try to prevent it but it’s not as simple as taking any calcium supplement in a hope that it will improve your bones’ health.

In order for the body to be able to absorb calcium, vitamin D is needed and indeed, many calcium supplements contain vitamin D in order to aid calcium absorption. However, this is not the whole picture. It gets more complicated.

If you want to maintain a healthy balance of calcium in your body it’s not only important for you to get enough vitamin D. Calcium works together with magnesium, vitamin K and phosphorus and you need to make sure you get enough of these nutrients as well. It’s actually really important to maintain the proper balance between magnesium, calcium, vitamin K2, and vitamin D. (2) The problem with calcium supplements is a lack of balance between these nutrients and this is the reason why calcium supplements have become associated with increased risk of heart attacks and stroke. (2)

Another problem with calcium supplements is that calcium comes in various chemical forms. Calcium supplement could contain calcium in a form of calcium carbonate, calcium orotate or calcium bound to various organic chelates (citrate, gluconate, lactate, amino acid) and there is more of course.(3)

Calcium carbonate is the most widely used form of calcium in supplements today but its absorption depends somewhat on the calcium becoming solubilized and ionized by stomach acid. (3) The problem here is that stomach acid tends to decrease as we age so taking this form of calcium when we are older is not a good idea.

You can now see why calcium supplements don’t work. There are so many variables involved. The best advice is to follow a healthy and balanced diet which includes all the nutrients needed for the body to absorb and regulate calcium. If you don’t get enough vitamin D through food or from sun rays, make sure you supplement and if you think you could be deficient take a test.

Are you taking any calcium supplements and will you continue taking them after reading this?


(1) http://bmjcom.c.presscdn.com/company/wp-content/uploads/2015/09/calcium.pdf
(2) http://articles.mercola.com/sites/articles/archive/2012/12/17/magnesium-benefits.aspx
(3) Mortimore, D. (2002) The Complete Illustrated Guide to Vitamins and Minerals. HarperCollinsPublishers Ltd.


  1. Great post. I don’t take calcium supplements and, after reading this, I don’t think I ever will. I’ll just try & get adequate amounts in my diet

    1. Thanks Helen. I also don’t plan to take any calcium supplements in the future as they seem to be doing more harm than good.