[HN Gopher] The Big Vitamin D Mistake [pdf] (2017)
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The Big Vitamin D Mistake [pdf] (2017)
Author : felineflock
Score : 55 points
Date : 2025-12-09 19:36 UTC (3 hours ago)
(HTM) web link (pmc.ncbi.nlm.nih.gov)
(TXT) w3m dump (pmc.ncbi.nlm.nih.gov)
| amanaplanacanal wrote:
| Interesting. I live at the 45th parallel, and try to get out into
| the sun everyday during the warmer months, with 5000IU orally per
| day during the gloomy part of the year. Now I'm wondering if I
| should get my levels checked.
| nerdsniper wrote:
| I've always been wary of overconsuming fat-soluble vitamins
| (ADEK). Seeing strong medical consensus that 6000IU/day of
| Vitamin D is safe and even desirable gives me confidence to
| supplement more liberally.
| erikig wrote:
| TLDR Unfortunately, medicine took a very long time to realize
| that vitamin D is not simply a vitamin that prevents rickets.
|
| We know today that vitamin D is a powerful nuclear receptor-
| activating hormone of critical importance, especially to the
| immune system.
|
| With the available data mentioned above, the proposed doses would
| probably suffice to maintain vitamin D levels around or over
| 75-100 nmol/L, with practically zero risk of toxicity.
| chasil wrote:
| My local grocery store offered free blood testing for Vitamin D a
| few years ago, and I was low.
|
| I take a 2000IU tablet a few times a week now.
| nikita2206 wrote:
| Haha the article states that the recommended daily dose should
| be 6-8k
| concinds wrote:
| Meanwhile, my daily 5000IU Vitamin D pills were recalled by some
| authority in Finland for "excessive dose", and since it appears
| that a recall anywhere in the EU will apply to the whole EU, I
| was given a refund and presumably won't be able to buy it again.
| euroderf wrote:
| 5kIU = 125 micrograms, that's a lot.
| anamexis wrote:
| The linked paper recommends 8000 IU/day for adults.
| concinds wrote:
| I doubt it has 100% bioavailability. Anyway, I don't trust
| the low "recommended" amounts.
| radicaldreamer wrote:
| In the US, you can get 50000 IU on Amazon, good enough for weekly
| supplementation if you're low (same as prescription strength).
| outime wrote:
| I've been taking 6000-8000 IU of vitamin D daily along with K2,
| with no issues. I recommend using drops instead of pills as they
| allow for more flexible dosing. They aren't more expensive either
| (in my experience, they're actually cheaper).
| josefritzishere wrote:
| This article is very technical and difficult to read. Is there a
| TLDR?
| anamexis wrote:
| The article's conclusion is straightforward.
| IAmBroom wrote:
| Nicely uninformative, but technically correct.
| egman_ekki wrote:
| Vitamin D good. Higher levels than previously thought.
| buildsjets wrote:
| Eat one small rock per day as important source of vitamins and
| minerals critical to digestive health.
| danvayn wrote:
| This is why I eat fruity pebbles.
| mrguyorama wrote:
| This article is not technical and is 4 pages and includes a 1
| paragraph executive summary. There's only 2 pages of content.
|
| There's no specific info about any experiment. It just claims a
| statistics error was recently found in another
| paper/experiment. It claims fixing the error suggests we should
| supplement more Vitamin D.
|
| It gestures vaguely at "Diabetes" and "immune health" and "we
| used to eat fish" to claim that we want/need more blood Vitamin
| D. It also points to some other actual studies that might have
| good evidence that we want or need more Vitamin D.
|
| I would doubt anything in this could cause harm. Vitamin D is
| fat soluble so taking too much can be dangerous, but I don't
| think the recommended doses here are close to that dosage.
|
| This paper aims for slightly more than 100nmol/l Vitamin D
| marker in blood, while other NIH papers claim >375nmol/l is
| getting into Vitamin D toxicity territory.
|
| >https://pmc.ncbi.nlm.nih.gov/articles/PMC6158375/
|
| NIH previously claimed a serum level of less than 72nmol/l is a
| health problem, so this paper is bumping that up slightly.
|
| My understanding is that large scale tests of Vitamin D
| supplementation don't ever seem to turn out as great as all
| these papers would imply. Maybe their experiments had too low a
| dose.
|
| My own supplementation has done jack and shit. Maybe I needed a
| higher dose.
|
| I still hold skepticism that all of humanity needs a
| supplement, as that's just a sales pitch from a company at that
| point, but the "Everyone really does need a shitload of Vitamin
| D supplement" hypothesis at least has a mechanism that makes
| sense.
| casenmgreen wrote:
| Do we need to be skeptical of NIH because of Trump? or they're
| still okay?
|
| Also, remember - don't take D on its own. Always with magnesium,
| or you get harmed by it, for all that it also does you good. Body
| is not built for raw D.
|
| Also also remember, D2 is a vitamin, D3 is a hormone.
| anamexis wrote:
| I don't think this paper is associated with the NIH besides
| being hosted there.
| Squealer2642 wrote:
| To be clear, NIH hosts an online database called PubMed that
| contains almost all published biomedical literature. If the
| article is open access, then it also hosts a copy of the
| article on PubMed Central.
|
| This is the link to the article in the PubMed database:
| https://pubmed.ncbi.nlm.nih.gov/28768407/
|
| You can click on the DOI link to go to the article hosted by
| the journal.
| beejiu wrote:
| > Also also remember, D2 is a vitamin, D3 is a hormone.
|
| As a naive person, what's the consequence of this?
| redblacktree wrote:
| These were strong claims, so I asked GPT. This is the
| response to that particular piece:
|
| "D2 is a vitamin, D3 is a hormone."
|
| This is biochemically muddled:
|
| Vitamin D2 (ergocalciferol):
|
| Plant/fungal-derived (e.g., UV-exposed mushrooms, fortified
| foods).
|
| Vitamin D3 (cholecalciferol):
|
| Produced in human and animal skin from 7-dehydrocholesterol
| via UV-B. Also used as a common supplement form.
|
| Both D2 and D3 are inactive precursors. They're hydroxylated
| to 25-OH-D, then to 1,25-(OH)2-D (calcitriol), which is the
| actual hormone that binds the vitamin D receptor.
|
| So:
|
| D2 and D3 are best described as prohormones (and
| traditionally called "vitamins").
|
| The hormone is calcitriol, not "D3 itself" as found in
| supplements.
|
| Functionally, both D2 and D3 end up as the same type of
| hormone (1,25-dihydroxyvitamin D), though their
| pharmacokinetics differ.
|
| The real difference between D2 and D3:
|
| Both raise 25-OH-D, but D3 is generally more effective and
| longer-lasting than D2 at comparable doses.
|
| So the line should NOT be taken literally. A more correct
| framing:
|
| "Vitamin D (whether D2 or D3) is technically a prohormone;
| its active metabolite behaves like a hormone. D3 is the
| human/animal form and is more potent than D2 at raising blood
| levels."
| more_corn wrote:
| If you dry mushrooms in the sun they contain a crap-ton of
| D2.
| buildsjets wrote:
| I mean, I agree MAHA sucks, and Kennedy is a fool and and
| loser, but the PDF is only hosted at the NIH. It was published
| in a journal owned by the Korean Society for Preventive
| Medicine, and the researcher is from Attikon University
| Hospital, University of Athens School of Medicine, Athens,
| Greece. And it was published WAAAAAAAY back in 2017.
|
| So do your research or something.
| Fire-Dragon-DoL wrote:
| I'm conflicted. It seems like in Canada the recommendation was
| that there was no actual error and the dosage of 1000 IU is still
| considered good. It's hard to find more than 2500 IU.
|
| I have no idea what to follow at this point
| woleium wrote:
| You can get 10,000 or even 100,000 IU tablets prescribed in
| Canada
| Fire-Dragon-DoL wrote:
| Yeah but to get a prescription you probably have to have a
| valid reason. If the general directive is that 1000 is fine,
| I'm assuming it's not easy to get a prescription for that
| sabareesh wrote:
| So is 10,000 IU of daily does ok ?
| woleium wrote:
| yes, but not long term, from what i've read. do it for 90 days
| through winter maybe?
| ChrisArchitect wrote:
| (2017)
|
| Some previous discussions:
|
| 4 months ago, flagged:
| https://news.ycombinator.com/item?id=44705486
|
| 2020: https://news.ycombinator.com/item?id=24768721
|
| 2017: https://news.ycombinator.com/item?id=15867918
| ChrisArchitect wrote:
| More recent Vitamin D discussions:
|
| _We 're learning more about what Vitamin D does_
|
| https://news.ycombinator.com/item?id=46088998
|
| _Vitamin D reduces incidence and duration of colds in those
| with low levels_
|
| https://news.ycombinator.com/item?id=45732670
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