Increasingly, research studies published in major medical journals conclude the same way: with a plea for more studies. The writers say they have found evidence leading them to believe that drug X “may be helpful” or drug Y "did not produce a measurable difference in outcomes" and urge additional testing to confirm (or presumably refute) their results. So, it was interesting to note that a recent study of vitamin D and bone health concludes not only that the authors found no evidence that vitamin D is beneficial in preventing or treating falls, fractures, or osteoporosis, but that also that no further study is warranted. The writers confidently assert that this latest study, a meta-analysis that examines all the well-done studies to date, including 45 recent studies that were not included in previous meta-analyses, should be the last word on the subject. Unless you have rickets or osteomalacia, two relatively rare conditions, the authors conclude that you should not bother to take vitamin D supplements.
In the past, the response to negative studies of vitamin D has been a chorus of “but, but, but.” But what about the effect of the dose of vitamin D—maybe 400 International Units is not enough to do anything but 800 is. The current examination looked at this question and failed to detect any difference in outcomes between people taking high dose or lower dose vitamin D. But what about the importance of age—can vitamin D make a difference in the oldest old, people at the highest risk of fracture? The current examination didn’t find any evidence it does. But what about the thickness of the bones at the time that vitamin D is initiated—maybe it’s too late to matter if there has already been a great deal of bone loss, but can be helpful at an earlier stage. The authors of the new report don’t think so.
Two years ago, I addressed the issue of vitamin D in my blog post, “Make No Bones About It.” I concluded that the evidence supporting vitamin D supplements was weak, but because falls and fractures are so devastating for older people and the cost of vitamin D is so low, with almost non-existent side effects, it wouldn’t hurt to take it—and maybe, just maybe, it might help. What do I advocate today? What will I personally do? Well, I still have a large bottle of vitamin D (1000 IU capsules) in my medicine cabinet. I’ll finish the bottle. Then what? Unless someone comes up with a compelling reason to continue, I’ll probably stop. But I will make sure to drink lots of milk, eat cheese, and get plenty of sunshine to ensure that my non-medicinal intake of vitamin D is sufficient.