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I’ve spent quite a bit of time reading the research on supplements over the past few years — and frankly, the more I read, the less inclined I am to use any. But there is one supplement I’m taking right now (having started a few months ago), and that’s vitamin D. I’ve heard enough enthusiasm from researchers I trust, and seen enough suggestive results, to decide that it’s worth a try — especially during the depths of a Canadian winter.
So why should I expect vitamin D to turn out any differently from all the other “miracle vitamins” that have preceded it and then been debunked? That’s the question that Tara Parker-Pope tackles in this entry on her Well blog. Her main point:
Although numerous studies have been promising, there are scant data from randomized clinical trials. Little is known about what the ideal level of vitamin D really is, whether raising it can improve health, and what potential side effects are caused by high doses.
And since most of the data on vitamin D comes from observational research, it may be that high doses of the nutrient don’t really make people healthier, but that healthy people simply do the sorts of things that happen to raise vitamin D.
Obviously, we need to figure these things out — which is where a new study comes in. The VITAL study is currently enrolling 20,000 older adults to take part in a five-year, placebo-controlled trial of vitamin D and omega-3 fatty acids. They’re looking for people all over the U.S. (no clinic visits are required, and all the pills will be mailed). If you’re interested, the details are here.
For now, I’ll keep taking vitamin D. But it’s worth remembering where the current research stands — and that many previous “miracle vitamins” have failed to pass the hurdle represented by the VITAL study.