Vitamin D and calcium tablets may not cut the risk of broken bones
Although I am a doctor, I am an obedient patient and do whatever my doctor (if I can get to see him) recommends.
Among the things he recommends is that I should take daily calcium and Vitamin D supplements, to reduce my likelihood of suffering a fracture.
Every year, about one in 60 adults over the age of 65 suffers a fracture of one kind or another – or one in 40 of those living in care homes.
It is no new discovery that older patients often do not recover fully from fractures, suffering continued pain, disability and loss of function thereafter. The prevention of falls and consequent fractures among the elderly is therefore a matter of considerable importance.
It helps me to be obedient that I find the chewable calcium and Vitamin D tablets, with a lemony taste, rather agreeable. When I told my doctor I liked his tablets, he looked at me as if I were mad – rather the way the QC did, when I told him I was enjoying my stay in Coventry when I spent a few days there as a witness in a murder trial, in which he was prosecuting counsel.
Whether they’re agreeable or not, it would be nice to know my calcium and Vitamin D supplements were doing me good: or, rather, that there was a statistically significant chance of its doing me good. So far, the evidence is lacking.
A paper in the British Medical Journal amalgamated the results of all the research trials that investigated the question of whether supplementation served to reduce the risk of fracture in elderly adults, excluding those with osteoporosis. There were 153,902 subjects in the trials, all of them aged 18 or over.
There was little or no benefit from calcium and Vitamin D supplementation, at least from the point of view of rate of fractures. The paper did not consider other medical conditions.
There was a statistically, but not clinically, significant protective effect of combined calcium and Vitamin D supplementation.
But it was so slight that it meant that 333 patients would have to be treated for years to avoid one hip fracture. Even this result was produced only because of a single trial, whose results were markedly out of keeping with all the others.
There is a certain caveat. Where many patients are lumped together, there might be a subgroup or subgroups whose positive results are swamped by the negative results of everyone else.
But, insofar as they were able, the researchers excluded this possibility, which did, however, remain. So it might be that very old and frail people in nursing homes, with a previous history of fractures, were protected by the treatment, but that they were too few in number to affect the overall result. The size of the fish you catch depends on the fineness of your net.
So if the supplementation (according to this research) does me no good, could it do me harm? There are potential side effects of supplements, sometimes serious, though only if the normal dose is exceeded.
These include high calcium levels in the blood, with increased thirst and frequency of urination, tiredness, muscle pain, confusion or psychological changes, nausea, vomiting, loss of appetite, changes of heart rhythm and bone loss leading to … fractures.
Am I going to stop taking the supplements, then? Mankind (in which I sometimes include myself) does not decide by reason alone.
I could be specially at risk because for two years I was on steroid therapy, which is known to thin bones, though I am no longer on such treatment.
But I like to please my doctor – so I will continue to take the supplements.
