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Are Vitamin D supplements over-hyped?


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The cover story of the latest Science News claims : "Vitamin D supplements aren’t living up to their hype--
Recent studies say taking extra amounts of the nutrient may not be a boon for every body"

Maybe the new findings don't apply much to CR folks, who need added amounts due to dietary restriction ??? In any case, vitamin D has been discussed extensively during the Mailing List days. And, IIRC, it was one of Michael Rae's "Tier 1" supplements.

https://www.sciencenews.org/article/vitamin-d-supplements-lose-luster

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  • 2 weeks later...

A good take on Vitamin D and Michael Holick here:

https://www.nytimes.com/2018/08/18/business/vitamin-d-michael-holick.html

I recall the vigorous debates in the old CR mailing list when Holick and his Vitamin D enthusiasm were coming to public prominence. As has been the case (e.g. Pauling and Vitamin C), the old routine of a credentialed, respected expert advocated a single molecule miracle turns out to be little more than unjustified hype that's served to further muddy the public morass of perceptions about supplementation, nutrition, and health.

If any good came of all this, it was that there was at least enough of a kernel of truth to get the IOM (now HMD) to revisit and modestly alter recommendations for Vitamin D.

As for the harm...one can only speculate regarding how many people were motivated to inadvertently give themselves skin cancer or hypervitaminosis D.

EDIT:
And regarding the usually reliable Michael-Rae-evidence-filter, worth mentioning the more up-to-date qualifications here: https://www.longecity.org/forum/stacks/stack/122-michaels-tiered-supplement/

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From the above Longecity link:

Quote

Michael Rae:     Do also make use of the relatively few reliable functional diagnostics for nutrient deficiency, such as serum 25(OH)D3 for vitamin D (target range should be 30-40 ng/mL ...)

Based on my research,  that seems like relatively sound advice (there are inevitable issues with test accuracy and  ideal target range, of course). I supplement vitamin d (along with K2)  at  level necessary to stay above 30ng/ml.

From the above NYT link:

Quote

Yet there’s no evidence that people with the higher level are any healthier than those with the lower level, said Dr. Clifford Rosen

That's grossly misleading, if not outright false.  It would be one thing to say that such evidence is disputed, inconclusive, inadequate, problematic, etc.  But it's just wrong to say that there is NO such evidence at all. 

Just consider the study  Michael Rae cites:

Vitamin D and mortality: Individual participant data meta-analysis of standardized 25-hydroxyvitamin D in 26916 individuals from a European consortium  February 16, 2017

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0170791
 

Quote

Michael Rae:  This is not only one of the most recent, but the methodologically strongest meta-analysis of the relationship between serum 25(OH)D3 levels and total mortality, giving strong evidence that the optimal level for 25(OH)D is ≈75-100 nmol/L [30-40 ng/mL]:

[...] Note that this addresses several complaints (reasonable and not) of megadose D advocates such as William B. Grant and Cedric Garland, including the use of unrepresentative high-risk and/or institutionalized populations in China and elsewhere, the lack of standardization of vitamin D levels, and underpowering. Note, additionally, that this is an individual patient-level data meta-analysis, which is a much stronger design than the more common (and much easier) straight-up mushing together of "high" vs. "low" quantiles from each study, irrespective of the absolute values represented in those quantiles.

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30-40 ng/mL appears to be a very reasonable optimum range for health.

As I've described previously, my experiment of last year consisted in regular full-body (only swim trunks) sun exposure from April troughout June, the month with maximum UVB radiation. Exposures were consistent and up to one hour and more around midday. At the beach the UVB dose was huge. I was very careful not to reach the eritema state, potentially hazardous for cancer (I also developed a good tan because of my Mediterranean ancestry). After this natural megadoses of UVB, my serum 25(OH)D3 level was 32 ng/mL.

Since the dosage was arguably a maximum natural dosage and the body shunts out excess  25(OH)D3 production, I can reasonably infer that the optimum level in my case was the level which was measured.

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