Calcium Supplements: More Risk Than Benefit?

Researchers are questioning the safety of calcium supplements as new data published in the British Medical Journal suggests a correlation between taking calcium supplements and an increase of heart disease and stroke.

Two studies involving 29,000 subjects indicated that supplementing with calcium may increase the risk of heart attack by a startling 25 percent and stroke by 15 percent. The first study examined the long-term effects of calcium alone. The second study (conducted by the same researchers) included vitamin D, since most people now take the two nutrients together. The results of the two studies showed exactly the same increase in risk, meaning that adding vitamin D made no difference.     

The surprising data poses the question of whether the risks of taking calcium outweigh the benefits. For every thousand people who took calcium for five years, six heart attacks were caused, but only three fractures were prevented. The researchers involved with this study suggested that calcium supplementation is not a very effective way to prevent fractures, especially considering the risk of developing heart disease.

The risks appear to be associated only with supplementation and not related to eating calcium-rich food.

Should you be concerned? Savvy consumers know that more than simply calcium and vitamin D are required for bone health. The bone matrix requires a complement of nutrients, including magnesium, boron, zinc and more. Among those, magnesium may be the most vital. While many calcium supplements include magnesium, the mineral is not emphasized as heavily as calcium or vitamin D is. More than 50 percent of American adults do not get enough magnesium – a preventive factor for heart disease - from food or supplements. (Read more here). 

While experts search for the mechanisms behind the increased risk of heart disease from taking calcium supplements, a one-to-one ratio of calcium to magnesium (plus vitamin D) or better yet, a more comprehensive bone-building mineral formula taken in addition to calcium-rich foods is your best defence against bone loss and osteoporosis.

Reference: Bolland, M.J., Grey, A., Avenell, A., Gamble, G.D., Reid, I.R. (2011) “Calcium supplements with or without vitamin D and risk of cardiovascular events: reanalysis of the Women’s Health Initiative limited access dataset and meta-analysis” British Medical Journal, doi:10.1136/bmj.d204.