Vitamin D study looking for participants


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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.

2 Replies to “Vitamin D study looking for participants”

  1. Each 1000iu/daily Vitamin D3 you take can at best raise status 10ng/ml 25nmol/l. Anyone with an inflammatory condition, Diabetes, Celiac, MS, Parkinson’s, Heart Disease, Arthritis, etc will probably require DOUBLE that amount to achieve the same rise in levels.
    Grassrootshealth have a graph in their banner showing recent 25(OH)D results from various intakes of D3. From this we see about half the people taking 2000iu/daily end up with levels below 40ng/ml 100nmol/l and thus will not have optimum bone mineral density, nor will they have any stored vitamin D3 nor will they provide vitamin D replete breast milk to their babies.
    This trial is designed to perpetuate the myth that low doses of vitamin D are adequate. In practice, in the UK it takes 4000iu daily to get around the 40ng/ml 100nmol/l mark and to have a store of D3 in reserve in your cells takes nearer to 6000iu/daily.
    The full text of
    Circulating 25-Hydroxyvitamin D Levels in Fully Breastfed
    Infants on Oral Vitamin D Supplementation
    is free online. Please read it.
    There you will find that at latitude 32N it takes 6400iu to achieve 58.8ng/ml and vitamin D3 replete human breast milk.
    Rather than starting from the lowest point at which most chronic illness is found we should be starting from the level human bodies, living naked outdoors naturally attain and maintain.

    The level associated with least chronic illness should be the starting point rather than the level that best suits those with a vested financial interest from providing services to ill people.

    Surely the level at which human breast milk becomes a complete food for babies is a natural biomarker for optimum status?

  2. Yes, the dose is certainly a key factor. Earlier studies have found little benefit from 400 IUs and 1000 IUs, which is why they’re trying 2000 IUs. Maybe it will, in fact, take 6000 IUs to see optimal benefit. But when you’re dealing with human subjects, the right way to do it is start by testing low doses, and then try higher and higher ones, rather than the other way around. If you yourself are convinced beyond a shadow of doubt that megadosing D3 is the way to go, by all means do it Linus Pauling-style. In the meantime, these careful, incremental tests serve an important role.

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