Calcium supplements, taken by very many women to ward off, or treat, osteoporosis, and other conditions, has been found to increase the risk of a myocardial infarction (“heart attack” to me and thee), by 31%. The researchers, at the University of Auckland, New Zealand, considered only those who took calcium alone, not with Vitamin D or anything else. Vitamin D, preferably as D3, as I’ve said here previously, aids the absorption of calcium, and should always be taken with it. What the significance of the research is for those supplementing properly – with calcium and D3** – is not yet known.
**What you’re likely to get from your doctor, in combination with calcium, is vitamin D2, which is what’s generally meant when vitamin D is referred to. No idea why, when D3 is more beneficial – either version costs buttons.
The research was not hard, people-based research, but meta-research, which is done by taking a bunch of research papers, and crunching the numbers – putting it simply. The problem I have with that, as regular readers may know, is that very often it fails to take into account the quality of the original research, which is worrying because, frankly, some research sucks. In this instance, at least, adequate numbers of test subjects had been used – 8,000 in 5 trials – so it seems reasonable to assume that other critical criteria were met as well. In poor research, they tend to skimp on the number of test subjects, which is pointless, as any results from a test population of less than 1,000 subjects is statistically meaningless.
And the question of whether it’s unabsorbed calcium, or any calcium at all, that’s the problem – as far as I can see from the report in Pulse ** – seems not to have been considered at this time (or, to put it another way, is the presence or absence of vitamin D the defining factor). To me, that’s surely a question of considerable importance?
**You’ll need to sign up to be able to read it.
Remember, though, that the NICE advice is to prescribe calcium and vitamin D in tandem, not calcium alone. Of course, GPs with an eye on the budget may just prescribe calcium alone (calcium and D are dirt-cheap even at retail prices, but I suppose it all mounts up.
“There was also a non-significant 20% increase in the incidence of stroke amongst patients on calcium supplements, and non-significant increases in death…” says Pulse Sorry, non-significant to whom? Well, actually, I think that it means that it can’t be directly ascribed to calcium. If it doesn’t, I’m at a loss.
Anyway, there’s no need to panic if you are taking calcium on its own, but if you are self-supplementing, add D3** to it, but in both cases, go and talk to your GP.
**D3 is more easily absorbed than just plain D, which is also more toxic. Unsurprisingly, perhaps, most prescribed supplements contain D2 (ergocalciferol), not D3 (colecalciferol)
Vitamin D isn’t prescribable, even though its deficiency, especially among the Asian population of Britain, is well documented. That strikes me as perverse. There is, though, no shortage of vitamin D supplements at retail level and, as always, if you buy your own, get D3.