You may have seen this story in the media recently where a study suggests that calcium can cause heart attacks. I nearly fell off my seat and started to look into it. However, just as I was doing that, Dr Marilyn Glenville sent a message through, which pretty much say everything I was going to say!
My own response is that I had already noticed that the research was not research at all as it was a review of studies already done, that there were very few trials actually reviewed, that the original research was not about calcium and heart attacks at all so info has been extrapolated which is always dangerous, that they used cheap chalk (calcium carbonate) instead of an absorbable form like calcium citrate, and, most importantly, they used cheap calcium on it’s own and not with its co-factors Vitamin D and magnesium for a start.
Studies done actually on this subject – the calcification of arteries – using calcium with co-factors has shown no risk at all, but these were not included in this review.
I despair sometimes. If I were trying to give drugs to a patient that I wasn’t trained in properly, there would be an outcry, but here are supposed medical professionals giving the wrong form of calcium in the wrong way. They are not trained in the use of supplements, yet are allowed to give them, whereas I am trained in their use and yet they are trying to stop nutritionists like me practicing! And the media ignore the facts and report the sensationalist stories – which we can’t blame them for as we buy the papers!
The basic fact you need to learn from this is that nutrients work together in synergy and taking anything out of context just isn’t the right idea. Calcium is important, but only if you take it correctly – think of all those people being given calcium supplements for osteoporosis. Thankfully now most of them contain Vitamin D, but hardly any contain the other co-factors like magnesium. See my previous post about magnesium being better than calcium for osteoporosis.
Anyway, I shall have a lie down whilst you read Marilyn’s full response!
“You may have read recently that taking calcium supplements has been linked with the risk of heart attacks for women. This is a result of the publication last week in the British Medical Journal of a review of 15 trials (available online at www.bmj.com/cgi/content/full/341/jul29_1/c3691).
Unfortunately, the more sensationalist press have, as usual, failed to temper their fear-inducing headlines by taking a closer look at the research itself. On my own examination, I have found out that the research review focused solely in studies that tested the effects of calcium taken on its own. Trials that examined a combination of calcium with vitamin D or other vitamins and minerals were excluded.
Indeed, the authors acknowledge that their review has limitations as none of the trials they examined were designed to look at heart attacks. It was only after the trials, which dated from 1993 – 2007, that they asked the lead investigator to provide data on heart attacks that occurred during the study.
Out of the 15 trials reviewed, the authors were only able to obtain patient data for five studies. 6 of the trials had only partially complete data, and there was either no data for the other 4 or no heart attacks had been reported. In addition, the review did not specify the type of calcium used. Calcium carbonate is literally chalk and it could possibly cause calcification in arteries if it is not get properly absorbed into bone. All in all not a very satisfactory research basis.
This was not a randomised, placebo controlled trial where one group was given calcium supplements and the other a placebo and followed over time to see if the calcium group had a higher rate of heart attacks. Other research comparing calcium PLUS vitamin D supplements (which were excluded from this review) with a placebo has shown that this combination of nutrients has no effect on the risk of heart disease or stroke.
My recommendation is always to take calcium citrate (not carbonate) with other nutrients – not only vitamin D but other minerals such as magnesium, because magnesium can offset any negative effects of calcium. ”
And I agree with that. Rant over!