
The Big Vitamin D Mistake - pacaro
https://www.ncbi.nlm.nih.gov/m/pubmed/28768407/
======
King-Aaron
Anecdotally, I had this discussion with a cardiovascular interventionist
specialist about seven or eight years ago when I was managing a team of cardio
theatre orderlies in a private hospital. He made the comment, "mark my words,
in about five to ten years time there will be a major scare about needing to
absorb more vitamin D".

His opinion was that the increase in sunscreen usage and the push to avoid
skin cancer by staying covered up was likely to blame. I find it interesting
when articles such as this pop up, because it directly reflects his concerns
from those years ago.

For reference, this was the late Dr Geoffrey Mews (who I only just realised
has passed on while I was looking for a reference to post. That's made me a
bit sad now)

~~~
deepGem
The NIH guys also did a study that said that even in tropical countries,
Vitamin D absorption has fallen dramatically because of lifestyle changes. One
of the probable factors is the lust for fair skin. I routinely see people
covered from head to toe to help them stay fair skinned, even kids are sent to
play covered in full sleeve clothing.

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897581/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897581/)

~~~
zeveb
> One of the probable factors is the lust for fair skin.

I think this must be cultural. Certainly in my experience in the United
States, the lust is for tanned skin. There are even tanning salons, where one
can lie down in a machine which floods one's skin with UV.

Now, I _personally_ love fair skin, and have never understood why others seem
to love a tan so much.

~~~
dsr_
It's a cultural thing, and directly related to wealth (or class, if you
prefer).

If most people work outside for a living, then the sign of wealth is that you
don't have a tan. If most people work in offices, then the sign of wealth is
that you have a tan, implying that you went on vacation or otherwise have the
available leisure time.

When most people do manual labor, having impractically long fingernails
demonstrates that you don't have to do that.

When most people have two or three sets of clothing, changing clothes several
times a day demonstrates your wealth.

When most people eat a subsistence diet, being fat is demonstrating wealth.
when most people eat fast food, being thin demonstrates your superior
resources.

If most people need to pay attention to what they are wearing at their jobs,
dressing in a way which signals that you don't have to pay attention is a
status marker.

If everybody drives a car, picking an unusual vehicle can be a status marker.
What's the difference between a Chevy Silverado 2-door and a Ford F-150 SVT
Raptor? They demonstrate different spending priorities.

------
dcx
Related to this topic, if you have IBS/IBD, some interesting research been
coming out in the last couple of years indicating that low vitamin D may play
a role in this issue as well. This [1] 2015 study found 82% of people with IBS
had low vitamin D levels relative to 31% in the control group. This [2] 2016
one _proved causation_ of vitamin D supplementation improving symptoms, by
randomly splitting into two groups and treating only one. This [3] speculative
writeup by the Vitamin D Council in 2014 discusses some possible mechanisms of
action.

This seems like such low-hanging fruit that it was extremely surprising to me
that this is at the cutting edge. Causes and cures for IBS are not clear and
one third of patients find current treatments unsuccessful [4]. But the above
doesn't seem to be well known in online discussion because it's so new, and my
gastroenterologist didn't bring it up at all either.

[1]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412886/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4412886/)

[2]
[https://www.ncbi.nlm.nih.gov/pubmed/27154424](https://www.ncbi.nlm.nih.gov/pubmed/27154424)

[3] [https://www.vitamindcouncil.org/health-
conditions/inflammato...](https://www.vitamindcouncil.org/health-
conditions/inflammatory-bowel-disease/)

[4] [https://www.vitamindcouncil.org/study-finds-high-dose-
vitami...](https://www.vitamindcouncil.org/study-finds-high-dose-vitamin-d-
supplementation-significantly-improves-irritable-bowel-syndrome/)

~~~
neonhomer
Anecdotal: I have Chrohns and take 2000 UI Vitamin D everyday. I've been
prescribed the lowest dosage anti-inflammatory (Mesalamine) for years and
rarely had a flare up. My Vitamin D blood tests always come back in the normal
level.

~~~
CWuestefeld
Another anecdote... I also take mesalamine (as Delzicol in my case), and take
3000 IU of Vitamin D (along with supplements of calcium, B-complex, and some
others). I almost never have flares.

However, I can't get a good colonoscopy - my GI doc says the prep is always
bad, even if I extend it for an additional day. He attributes that to a
chronic simmering inflammatory state preventing things from cleaning out well.
That puts me at a much higher risk of colon cancer, and so I'm also doing
Entyvio infusions prophylactically.

~~~
ianai
Have you tried going to a different doctor?

------
micro_cam
This article seems to be a low quality review of other research with a
clickbatey title (full text here:
[https://www.jpmph.org/journal/view.php?doi=10.3961/jpmph.16....](https://www.jpmph.org/journal/view.php?doi=10.3961/jpmph.16.111)).

Pubmed is sort of like arxiv.org and the fact this has an nih.gov base url
should not be taken as an endorsement of it by the NIH.

That said I do actually believe that more then the recommended amount of
vitamin D can be beneficial and the recommendations are in need of
reevaluation.

~~~
davidshepherd7
Just to back this up: the journal it's published in has a very very low impact
factor of 0.235 (i.e. it publishes 4x more papers that it gets citations,
probably most of it's papers are never cited by anyone) [1]. If this paper was
considered a big a deal by the wider research community you would expect it to
be published in a high profile journal.

[1]:
[https://journal.komci.org/ViewJournalInfo.php?JID=109#Impact...](https://journal.komci.org/ViewJournalInfo.php?JID=109#ImpactFactor)

~~~
jooke
Do you know why this is the case? Is there some flaw in their methodology?

~~~
patkai
Good question! The scientific method does not include references to "impact
factor" :)

~~~
drostie
I mean, it does. The "fairy tale" that one hears in high school doesn't, but
we put aside fairy tales when we became adults.

If you are done with the "undergrad level" of Popper and Kuhn it is worth
reading Imre Lakatos's work on philosophy of science. It contains a moment
where one realizes that research programs live or die by this "impact factor"
and that this living or dying is a key part of the overall methodology of
science. The gist is that science is actually participating in a survival-of-
the-fittest evolution with certain foundational ideas as the "genes" which
"reproduce". So scientific ideas are actually good or bad in no small part due
to their ability to create further scientific research along similar lines. A
low impact-factor therefore directly says "along this particularly important-
to-science axis, this journal sucks."

~~~
alex_stoddard
But to stretch the analogy a bit further would it be fair to say that impact
factor is very like sexual selection for extreme display traits that otherwise
are detrimental to the wellbeing of the species?

Yes impact factor matters to current science as practiced but there is plenty
of good criticism to show (at least as it is currently calculated) that it is
a lousy measure of what is likely to end up being true, reproducible and
useful.

~~~
throwawayjava
_> would it be fair to say that impact factor is very like sexual selection
for extreme display traits that otherwise are detrimental to the wellbeing of
the species?_

If I read every PoS article vaguely related to my research, I'd never get
anything done. In practice, I don't pay attention to impact factor. But I do
pay attention to who's publishing. And that's basically the same as impact
factor, in practice.

 _> that it is a lousy measure of what is likely to end up being true,
reproducible and useful._

I don't think so.

High impact factor publications are _MUCH_ more likely to be quality science
than low impact factor publications (at least in my area).

The major venues would have to get at least two orders of magnitude worse
before they became bad indicators of quality.

Of course, and obviously, that does not entail that all work published in high
impact factor journals is high-quality.

I think the fundamental problem is just that you vastly under-estimate the
enormous volume of utter crap there is out there.

------
tathougies
This supports my lived experience. Found to be incredibly low in vitamin D,
and diagnosed with autoimmune thyroiditis. Doctor said to supplement with 2000
IU being the max per day.

After seeing no improvement whatsoever in vitamin D levels, and after talking
with others with the same issue, I self medicated to 10000 IU / day.

Lo and behold my vitamin D levels went back up and my auto-antibodies went
back down.

~~~
20years
This is similar to my lived experience. I was diagnosed with Hashimoto's 3
years ago. I was lucky to find a great doctor that specialized in it. He put
me on 15000 IU / day for 3 months because I was so severely low in addition to
having high antibodies. Within 3 months my levels were so much better. I still
take 10000 IU / day along with selenium, iron, fish oil and good diet/exercise
and all my levels have been in check for 2 years :)

~~~
Flow
Could you write a bit about the role of selenium in your treatment? Thanks.

~~~
20years
Sorry just now saw this. The article here goes into things pretty well for my
situation at least [http://www.lifeextension.com/protocols/metabolic-
health/thyr...](http://www.lifeextension.com/protocols/metabolic-
health/thyroid-regulation/Page-08)

I don't want to give any kind of medical advice especially without knowing the
situation of others. If you are concerned though, it doesn't hurt to get blood
work done. Following are the common things to test for if you think you may
have Hashimoto's or thyroid issues.

Vit D, Ferritin, Thyroid peroxidase antibody (TPO), Thyroglobulin antibody
(TGAb), Thyroid-stimulating hormone (TSH), Free T4 Test

------
jhwhite
Could someone help me understand this?

>it was found that 8895 IU/d was needed for 97.5% of individuals to achieve
values ≥50 nmol/L. Another study confirmed that 6201 IU/d was needed to
achieve 75 nmol/L and 9122 IU/d was needed to reach 100 nmol/L. The largest
meta-analysis ever conducted of studies published between 1966 and 2013 showed
that 25-hydroxyvitamin D levels <75 nmol/L may be too low for safety and
associated with higher all-cause mortality, demolishing the previously
presumed U-shape curve of mortality associated with vitamin D levels.

What is IU/d? What is nmol/L? Could someone ELI5 the entire abstract for me?
Well, maybe a little more than 5, I get that there was an error estimating
recommended levels and we're not getting enough.

~~~
floatingatoll
The generally accepted goal by both the researchers and the US RDA is to reach
50-75 nmol/L blood levels, using however many IU that takes.

IU/d is "IU per day of Vitamin D", and nmol/L is "nmol per liter of blood".
Vitamin D is measured in IU rather than grams like most other supplements for
medical reasons I'm not familiar with. nmol is an unfamiliar unit, but I can
help clarify why this paper is so stunning anyways.

[https://ods.od.nih.gov/factsheets/VitaminD-
HealthProfessiona...](https://ods.od.nih.gov/factsheets/VitaminD-
HealthProfessional/) is a summary of the NIH's position on Vitamin D for US
citizens. The research linked by this post differs in two key ways,
approximately:

First, "<75 nmol/L may be too low for safety", vs. the NIH statement ">50
nmol/L generally considered adequate" (for adults).

Second, "8895 IU was needed to reach >50 nmol/L", vs. the NIH statement "600
IU sufficient with minimal sun exposure" (for adults).

So, in summary, for healthy adults, they assert that 10-20x the current RDA-
indicated IU of vitamin D consumption is necessary to achieve the recommended
blood saturation level of 50-75 nmol/L in all adults.

Two notes: These precise figures are for grown adults, NOT children; and, I
strongly encourage getting a vitamin D blood test before starting or modifying
your vitamin D supplement intake, especially if attempting to reach the 15x
RDA levels described here.

~~~
logfromblammo
IU are used whenever a particular vitamin has multiple forms with varying
levels of efficacy [0]. Or it may be used when the typical quantities are
measured in inconveniently small units.

1 IU of cholecalciferol is 0.025 micrograms. If you supplement vitamin D at
hogh doses, make sure you use cholecalciferol rather than ergocalciferol. The
former is naturally synthesized in your own skin, whereas the latter is
produced mainly in mushrooms, and can result in unpleasant side effects.
Maximum-dose recommendations from nutritionists may include the assumption
that the consumer does not know the difference, therefore reflect the highest
safe dose of the least-safe vitamer.

It is similar to the issues with vitamin A, when someone may safely supplement
with carotenes and unsafely supplement with retinol. You can eat sweet potato
and carrots until you turn orange, but you cannot eat a single bite of polar
bear liver. But because we are mostly idiots, nutritionists cannot recommend a
high-dose supplement for vitamin A, with carotene in mind, because someone
will inevitably overdose themselves with retinol. So if you can certify
yourself as not-a-moron, you will be able to figure out when those
recommendations may be safely ignored.

[0]
[https://en.wikipedia.org/wiki/Vitamer](https://en.wikipedia.org/wiki/Vitamer)

~~~
Asooka
Where can one go to learn about different forms of vitamins and the
safe&recommended doses for each?

~~~
floatingatoll
The other reply to your comment is entirely valid and I encourage you to read
it in full.

That said, the only way to measure a safe dose of a vitamin is to perform
medical tests before and during a dosing regimen to ensure that you are
neither under nor over the target levels of the vitamin in your body.

Medical science is not yet reliable when it comes to defining target levels of
vitamins in any individual's body.

In general, for all body dosing regimens, the goal is to survive the dosing
changes without dying _first_ , and to produce the desired result _second_. If
you are not treating a specific symptom and instead wish to simply calibrate
your blood levels to "optimum", be warned: There is no optimum, period full
stop.

For example, if you increase your vitamin D levels precisely to a target
amount with careful blood testing and supplement regimes, then your risk of
death from sunlight exposure may increase if/when the levels of sunlight
you're exposed to shift significantly (due to work, weather, or travel). Some
will immediately object that the increase in risk is vanishingly small. You
are irreplaceable. What level of risk of death of acceptable to you?

Soylent calibrates their food product to 100% of all doses specified by the US
RDA for healthy adults. It's generally assumed to be a safe set of targets,
though some would say that it is too low in many respects (while missing the
bigger picture of the 'pick one' conflict between society-level dosing and
individual-specific dosing), and others would say that it is too high in many
respects (while missing the bigger picture of the 'pick one' conflict between
increased risk of side effects vs. increased risk of malnutrition).

There's a good reason why everyone ends up at the same sentence, and I'm going
to provide it now:

Seek advice from a medical professional before consuming supplements. If you
are unwilling to do so, get a med-alert bracelet and keep a summary of the
past year of dosing changes in your wallet. It may someday save your life. If
you are unwilling to wear a med-alert bracelet and keep a log of your self-
alteration efforts, consciously accept that you risk death if unintended
consequences occur.

------
rmm
I have been taking 5000IU Vitamin D for the past 7 years, with a little more
over the winter months. It's stupidly cheap, I get 360 5000IU capsules for
$13, so it has cost me less than $100 over that period.

Anecdotally, it was a game changer for me personally. I got less sick during
the winter, and my overall wellbeing improved greatly.

A word of advice, increase Vitamin K intake aswell. Vitamin D helps calcium
absorption, but Vitamin K directs it to where it needs to go (skeleton).

~~~
Styn
Word of advice: don't take vitamins ADEK without advice from a physician for
extended periods or in high doses. These are fat soluble so you can have too
much of them.

~~~
avip
This should be reiterated: Please consult a professional before drastically
altering the chemical composition of your ephemeral body.

I know it sounds downright crazy, but it's possible that someone who's studied
medicine and practiced it for years, actually knows better than random
anonymous forum users.

~~~
icelancer
>>I know it sounds downright crazy, but it's possible that someone who's
studied medicine and practiced it for years, actually knows better than random
anonymous forum users.

As the link in the OP actually denotes, no, that's not always the case.

Bodybuilders and performance trainers - as well as Soviet Union sports
scientists - have known for decades that Vitamin D supplementation is vital.
This has been rejected by a significant number of general practitioners and
other medical experts who are and were anti-supplement simply out of rote
thinking.

Yes, people should be tested for their levels. But this simply isn't feasible
for poor people, and telling them to get serum tests for Vitamin D before
taking a lower-bound amount of the cheap supplement from the grocery store is
ridiculous.

~~~
lostlogin
I don’t think that the drug regimes of the Soviet Olympic Teams should be held
up as a good example to follow - a lot of damage was done to a lot of people.
On a related note, the Russian team just got banned for trying that crap
again.

[http://www.rollingstone.com/sports/news/russia-banned-
from-2...](http://www.rollingstone.com/sports/news/russia-banned-
from-2018-winter-olympics-over-doping-scandal-w513380)

~~~
myth_drannon
That was mostly political decision, many American/Norwegian/... are legally
taking performance enhancing drugs.

------
noahdesu
Has anyone had experience ordering blood work (e.g. the vitamin d 25 hydroxy
test) without visiting a doctor? I've seen very few references to the set of
sites that pop up first online [0, 1, 2, 3] when I've gone looking for reviews
in the past. Any suggestions? I'm in CA.

[0]: [https://www.privatemdlabs.com](https://www.privatemdlabs.com) [1]:
[http://www.directlabs.com/](http://www.directlabs.com/) [2]:
[https://www.walkinlab.com/](https://www.walkinlab.com/) [3]:
[https://www.health-tests-direct.com/](https://www.health-tests-direct.com/)

~~~
pauljurczak
In case you have a health insurance - many plans provide a free yearly
preventive care doctor visit, which include basic blood lab work. I took
advantage of it many times with different insurance companies.

~~~
batter
I'm not sure it applies to US where Health Insurance is rather russian
roulette when you need coverage. Not sure about Aetna, but BlueCross is pretty
clear: "BCBSNC will provide coverage for testing serum vitamin D levels when
it is determined to be medically necessary because the medical criteria and
guidelines noted below are met."
[https://www.bcbsnc.com/assets/services/public/pdfs/medicalpo...](https://www.bcbsnc.com/assets/services/public/pdfs/medicalpolicy/testing_serum_vitamin_d_levels.pdf)

I just recently have been struggling with coverage of Vitamin D test for kid
with Celiac.

------
ravar
Throwing in my two cents. I used to suffer from seasonal mood swings, since
taking a daily multivitamin this has been the best winter of my life.

~~~
themodelplumber
I've been tracking my depression for a few years now, and I'm amazed at the
number of things that can trigger a depressive episode. I used to think I had
a disease called depression, but it now appears that I had arrived at a
collection of various life circumstances that made experiencing depression on
any given day more likely for me.

Some of the main triggers have been:

\- Attempting to proceed without a plan

\- Pushing for more productivity when less is called for (New year's
resolutions were a great example personally)

\- Bad sleep (I now use the calculator at sleepyti.me and have had great
results)

\- Too much exercise without rest days

\- Too much exposure to social experience

\- Too few dopamine-injecting experiences (e.g. not enough achievement, not
nibbling away at my problems and watching leverage build up)

Strikingly to me, some of these seem tied to my psychology and I would
hesitate to tell others "hey not having a plan is bad for you" when I know
some people for whom planning is a mental health liability. Personalized
medicine can't get good enough, fast enough.

~~~
jventura
> Bad sleep (I now use the calculator at sleepyti.me and have had great
> results)

Interesting site, didn't knew about it!

I've checked it out, and as I wake everyday at 7am, it suggests me four
different hours: 10pm, 11:30pm, 1am and 2:30am. What I find interesting is
that none of it matches exactly the 8h average sleep value. As you say that
you have had great results, could you comment a little bit on that?

Thanks!

~~~
twobyfour
8 hours is typically time from bedtime to wake time. It allows for some time
spent falling asleep, and maybe one wake-up to visit the bathroom.

You'll notice that your suggested wake times are an hour and a half apart.
Natural sleep cycles tend to run about 90 minutes (on average). So 7.5 hours
would be 5 cycles. 8 hours is 5 cycles plus that buffer time.

I haven't used the app you mention, but I have begun a habit of getting out of
bed between cycles instead of whenever in the cycle my alarm goes off. It
definitely increases morning alertness and willingness to get up. Not sure it
affects restedness much.

And I've been measuring my sleep in cycles (or at least in 90 min increments)
instead of in hours - which gives me a much clearer perspective on how much
I've had and need.

------
yufengg
tl;dr: we need wayyy more Vitamin D than previously recommended. ~13.3x more.
Take supplements to reach 8000 IU/day for adults.

existing standards from the NIH: [https://ods.od.nih.gov/factsheets/VitaminD-
HealthProfessiona...](https://ods.od.nih.gov/factsheets/VitaminD-
HealthProfessional/)

~~~
skybrian
However the article doesn't describe any new research and cites a meta-
analysis that has a different conclusion:

"A target range of 25(OH)D of greater than 30 ng/mL could be achieved in most
individuals by intake of approximately 1000 IU per day of vitamin D3, which is
one quarter the National Academy of Sciences–Institute of Medicine tolerable
upper level of intake of 4000 IU per day at ages 9 years and older. Although
it is above the National Academy of Sciences–Institute of Medicine–recommended
daily allowance of 600 to 800 IU per day, intake of 1000 IU per day has been
reported as safe for daily use for almost all adults, according to the recent
Endocrine Society clinical guidelines. Still, some authors have expressed
concern about the efficacy and absolute safety of doses greater than 1000 IU
per day, so caution is reasonable. The Endocrine Society has established a
tolerable upper-limit intake of 10 000 IU per day at ages 19 years and older.
Doses of vitamin D3 below 10 000 IU per day in adults have not been associated
with toxicity, and serum 25(OH)D concentrations less than 200 ng/mL are
generally not considered toxic. This leaves a considerable margin of safety
for efforts to raise the population concentration of 25(OH)D to 40 ng/mL."

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103214/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103214/)

------
growlix
Interesting that this stems in part from misinterpretation of confidence
intervals. The referenced paper, A Statistical Error in the Estimation of the
Recommended Dietary Allowance for Vitamin D [0], seems like an excellent
example to illustrate how (and how not) to interpret confidence intervals.

[0]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/#!po=22...](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/#!po=22.5000)

------
moonka
A couple years after I moved to Seattle I started noticing some odd aches and
pains. After a coworker had similar issues, I went to the doctor, and they
tested my Vitamin D levels. They were ridiculously low. They had me on a high
initial dose, and than taking supplements ever since. I've heard the same
story from tons of neighbors. Nowadays it's one of my first suggestions for
new transplants. It's made a marked difference (along with a sunlamp).

~~~
Mouse47
What sorts of aches and pains? I'm only asking since my body just effing hurts
sometimes, usually my upper back/ribs...especially when I'm stoned :/

~~~
Double_a_92
Not OP, but I had a similar experience. In my case it was stomach and bowel
pains, like cramps... combined with anxiety without reason.

------
andy_ppp
If you intend to take vitamin d I read in various places you should also take
magnesium and probably vitamin k as well. And less calcium. Everything is
interconnected.

[https://www.precisionnutrition.com/stop-
vitamin-d](https://www.precisionnutrition.com/stop-vitamin-d)

~~~
guilty001
I recently started taking 3000mg of magnesium per day as magnesium chelate.
The bottle recommends three capsules per day for muscle spasms / cramps.

Historically, I have a couple of basic assault charges, an assault with sexual
intent charge, I was charged with two counts of trafficking a controlled drug
(later dropped).

Shortly after I commenced taking six capsules a day I started feeling a _lot
less psychotic_.

~~~
0xJRS
I would also recommend taking Zinc with it. I was taking Magnesium at one
point by itself and developed a muscle twitch which was fixed by adding Zinc.

~~~
guilty001
Yep, been taking zinc as zinc chelate and / or zinc gluconate for years.

------
creep
About once every 6 months I remember to start taking my vit D supplements
again. I've always taken more than the recommended dose because vitamin D is
not extremely bioavailable in pill-form, and I notice amazing improvements in
mood, mostly. Usually I am sad in the mornings. I have a cup of coffee, browse
around on HN, and then convince myself to do work, and the sadness goes away
with the distraction, and by the evening I feel pretty good for "doing so much
work". When I take vitamin D, after about a week I begin to wake up and set to
work immediately, leaving time in the evening for fucking around. I really
should do that now, before finals.

~~~
whowouldathunk
Same experience for me. The University of Washington headache clinic
recommended Vitamin D and Magnesium supplements and it made a marked
difference in my mood. Turns out having constant mild headaches is pretty
depressing.

~~~
noir_lord
Have to be careful with magnesium, too much and you'll spend the entire day on
the toilet been reminded that topologically humans are a tube.

~~~
creep
This effect is more pronounced with lower-quality magnesium supplements, such
as magnesium oxide, magnesium sulfate, and magnesium chloride. These compounds
are insoluble in water (magnesium oxide), or their counter-ions are not
absorbed (magnesium sulfate). Magnesium + glycine (specifically bisglycinate
which is the magnesium salt with two glycine molecules) is more bioavailable
and does not have a laxative effect since glycine is easily absorbed by cell
walls. Magnesium citrate also does not have a marked laxative effect and is
more bioavailable than magnesium oxide, but less bioavailable than magnesium
bisglycinate.

~~~
noir_lord
Thank you for the info, I'll check those out, my medication is thought to
affect nutrient levels so I take supplements (I found out about the laxative
effects myself..)

------
piotrkaminski
Coincidentally, another submission from earlier today points to a study that
says that (lack of) Vitamin D can impact sleep quality:
[https://news.ycombinator.com/item?id=15862222](https://news.ycombinator.com/item?id=15862222).

------
theprotocol
If the recommendations of this study become the guideline, it may validate the
other studies suggesting that nearly everyone is deficient in magnesium, which
is a co-factor in the Vitamin D / calcium cycle.

AFAIK (and correct me if I'm wrong), the vitamin D metabolism requires
magnesium, calcium, vitamin K2, and vitamin A. K2 in particular needs special
attention, as it's the hardest of the substrates to get.

~~~
skybrian
It's not a study. It's an article that cites other studies.

~~~
theprotocol
It has an abstract, so I figure it's a meta-analysis and not just an article.

~~~
skybrian
It's not a meta-analysis either. It cites a meta-analysis, which has different
conclusions.

------
borplk
Steve Gibson has talked about this issue in the past:
[https://www.grc.com/health/vitamin-d.htm](https://www.grc.com/health/vitamin-d.htm)

(And please, yes we get it you are a smart ass, don't link to the page that
you are going to. The horse has been beaten to death.)

~~~
skeleton
Now I'm curious as to what page you're referring to.

~~~
borplk
I'm not going to refer to it. If you are curious search on google or HN.

~~~
simias
It seems dishonest to hide content that may be relevant to the discussion,
especially after teasing it that way. Maybe if it warrants mentioning in your
original comment it also warrants explaining why you think it's irrelevant?

~~~
borplk
There's no dishonesty. They are easily found for anyone interested. As I said
the horse been has beaten to death so I didn't want to do what I was
discouraging others from doing.

They are mostly uneducated, lazy, decade-old, hand-wavy, and baseless personal
attacks on him.

The man has been a geek, engineer, programmer and a techie for multiple
decades.

He has been on record for the past 12-13 years audio, video and text
transcripts, 2-3 hours per week, discussing many topics in detail, explaining
his thoughts and ideas and reasoning carefully (on SecurityNow podcast, 600+
episodes!).

Every time he has made a mistake he comes back and carefully corrects himself,
and it doesn't happen often either.

He is no Linus Torvalds, and he doesn't claim to be one, most of us aren't
either.

And his knowledge goes into all sorts of weird corners from science fiction to
medicine like the vitamin D stuff and the "sleep formula".

All of it available for free for anyone who has the patience to sit through it
and learn. I have, and he has improved my life in many ways that I owe him for
and can never pay back (including starting to take vitamin D many years ago
after he talked about as I have referred to).

He has contributed positively to this community and industry for many years.
He has done nothing to deserve people bringing up stupid pages that call him a
"charlatan" or "snake oil salesman" every time someone calls his name.

There isn't even any substance to those claims. Most of them say "he said XP
raw sockets were bad!! GET HIM!!".

Or variations of "Spinrite doesn't fix prostate cancer. It must be snake oil
software.".

He has probably explained 10+ hours on SecurityNow the history behind
Spinrite, what it does, what it doesn't, why it works, where it works, where
it doesn't work and everything in between.

But these bitter 20-something neckbeards are too busy for that. Let's jump the
man that has been a programmer for longer than you have existed because he
uses assembly or something ... GET HIM!

I have no horse in this race. I'm just angry at the smug reply that inevitably
follows every time him or his pages/products/projects are mentioned.

As if everyone needs to be warned about this monster of a man for the
unimaginable sins he committed 10+ years ago when he said something about XP
raw sockets, or something else.

If these people criticising him had produced a tenth of the content that he
has produced they would have made many more mistakes.

What are we to do now? Crucify Gibson because his Spinrite software doesn't
perform miracles? Or because he has made a few mistakes here and there?
Everyone else is perfect?

Are we going to dig up the past history of everyone else who is mentioned too?
And link to a page that enumerates the minor mistakes they have made over
their entire career?

Go dig up Github commits to shame people who introduced stupid bugs in open
source software? (not that he has, just an example)

Or how about we dig through their medium posts, conference presentations, and
list and archive any possible mistakes.

Then every time someone mentions them say "HEY LOOK EVERY BODY THIS PERSON HAS
MADE 3 WHOLE MISTAKES SINCE 10 YEARS AGO, THEY ARE CLEARLY A MONSTER! STAY FAR
AWAY.".

It is completely uncalled for and has gotten real old.

He doesn't come here to write something like this himself so I had to do it
for him.

Steve, if you ever read this, thank you for your work.

Edit: fixed some typos, added some additional sentences

~~~
RankingMember
Jesus man, I think you overestimate the amount of people with an axe to grind
against Steve Gibson and you're letting whatever negativity, real or imagined,
majorly distract from your original comment.

------
juskrey
But who said increasing of serum levels of Vitamin D by pills intake will
decrease mortality??

What about side effects of such massive UNCONDITIONAL top-down
recommendations?

------
kieranmaine
This older paper suggests vitamin D isn't as important -
[https://jamanetwork.com/journals/jamainternalmedicine/articl...](https://jamanetwork.com/journals/jamainternalmedicine/article-
abstract/2478893?redirect=true). I'm not sure which is correct, but good to
have an opposing view.

~~~
skoocda
This paper suggests that increasing vitamin D intake from 800 IU/d to 2000
IU/d doesn't increase the risk of falling over and fracturing a bone.

I wouldn't call that especially relevant, and it's definitely not an opposing
view.

------
timewarrior
This article recommends around 100 nmol/L. Most people are between 20-30,
because they don't get enough Sun and do not take supplements. It gets really
really bad when the number gets below 10 and it takes months to recover.

Another Vitamin whose deficiency cause irreversible damage is B12. Folks, get
both of these checked.

~~~
DigitalJack
I happen to have a gene mutation that makes methylation of B12 inefficient. I
never did well in chemistry or biology for that matter, but my limited
understanding is that methylation is necessary for it to be useful.

It turns out that you can buy methylated B12 called methylcobalamin. The more
common form is cyanocobalamin, and is not very useful for people like myself.

That is my understanding, if anyone here knows better or more, please correct
me.

~~~
timewarrior
Thanks for this added information. I discovered the same thing, with another
family member where Methylcobalamin worked wonders and Cyanocobalamin didn't.

One thing I would add is that Methylcobalamin needs to be injected to work
best. If people do not have your gene mutation, they are better off taking
Cyanocobalamin.

PS: Whenever someone in family has major health issue which no one can get
handle on - they reach out to me. My lifelong dream has been to cure Cancer
using AI. Just started working on that.

~~~
pcthrowaway
I thought the injection was typically hydroxocobalamin. Has this changed?

~~~
timewarrior
Yep, they are and also the best form. Extremely unstable in capsules and oral
supplements though.

Methylcobalamin isn't very effective orally. However someone with a gene
mutation doesn't have any choices.

~~~
AstralStorm
It actually is quite effective, much like cyanocobalamin. (The usual form in
supplements.) Needs just slightly higher dosage than hydroxocobalamin.

------
klht
Everyone supplementing and doing their own tests should be careful to note the
difference between nmol and ng/ml.

100 nmol = 40 ng/ml

ng/ml is the most common measure in India and many other places.

~~~
tgb
Uh, you should be careful too! There's some error in what you wrote too. Is
that nmol/L that you mean?

~~~
cypherpunks01
What is the correct conversion? Quest, one of the dominant lab providers in
the US, reports in ng/mL and I'm not sure how to interpret my result in
nmol/L.

------
tw334
what is this saying in plain english? That we all need to take vitamin D
supplements?

~~~
mborch
or better, just spend more time outside.

~~~
rapsey
The amount of disinformation commonly expressed about vitamin D is quite
amazing.

Bogus claims:

1\. Spend a couple of minutes outside and you will be OK.

2\. It is absorbed through the eyes.

3\. Deficiencies are rare.

When in fact:

1\. Does not apply at any time when your body is covered up mostly. Wear
trousers and a T-shirt and you've cut yourself off severely already. Add
weather with less sun, sunscreen, and/or more clothes and you've cut yourself
off almost entirely unless you are outside for very long periods of time.

2\. Fuck no.

3\. They are extremely common even in sunny places. In the developed world a
majority of people are.

~~~
bbunix
You'd think sunny places would fare better - however after moving to Key West
from Montreal I discovered people here spent a lot of effort _avoiding_ the
sun (skin cancer is big down here).

~~~
ianai
As someone with fair skin, I’d be harming myself if I tried to get vitamin D
from the sun. And very badly.

------
olympus
Hmm. "Actions are urgently needed to protect the global population from
vitamin D deficiency." I wish this sentence wasn't in the abstract, because
it's the first thing the "science journalists" are going to latch on to. It's
not like people's bones are snapping because everyone has rickets. Maybe not
an urgent need, just something we should publish a revised RDA and diet
guideline. We had a very different looking food pyramid when I was growing up,
but changing it didn't drastically increase life expectancy. Everyone choking
down extra vitamins isn't going to fix a non-existent problem.

------
BeetleB
I see a number of comments about taking Vitamin D for mood and SAD issues.

My goto site for supplements is
[http://www.informationisbeautiful.net/visualizations/snake-o...](http://www.informationisbeautiful.net/visualizations/snake-
oil-scientific-evidence-for-nutritional-supplements-vizsweet/)

It essentially ranks supplements based on the amount of research there is to
support the claim (so the same supplement can show up in multiple categories).
You can see Vitamin D is backed by a lot of research for various ailments, but
the category for which there is least evidence is mood related disorders.

On a side note, be very wary of the supplements you take (in the US). There is
virtually no oversight in their manufacture, and various groups'
investigations have shown that the claimed dosage can be way, way off. And the
inactive ingredients may be false as well. Relying on well known companies did
not seem to make a difference.

I recall an interview with a pharmacist at a hospital that had decided they
test the supplements they had in stock - given that they were giving them to
patients. They were rather shocked.

If anyone has a good resource where a group tests different manufacturers'
supplements and has some kind of reliability rating, I'd love to know. I
pretty much stopped taking supplements when I saw how unreliable the claimed
dosages were.

~~~
XzetaU8
For me Examine.com is the best source on supplements/vitamins

take for example Vitamin D
[https://examine.com/supplements/vitamin-d/](https://examine.com/supplements/vitamin-d/)

as for your question regarding Supplement manufacturers test check labdoor
[https://labdoor.com/](https://labdoor.com/)

~~~
BeetleB
Looking at Vitamin D on Labdoor:

>6 of the 19 products in this report exceeded their label claims by greater
than 40%.

>All 19 vitamin D supplements met or exceeded their claimed vitamin D3
content, ranging from +0 to +900.0 IU versus their stated label claims.

>The average label variance in this testing batch was 22%.

Wow.

Let's look at melatonin:

>Only half of the products tested (15 of 30) measured melatonin levels within
10% of their label claims. 7 products deviated from their claims for melatonin
by at least 25%. 3 of those products recorded 40% or more melatonin than their
label claims, and 1 product had less than 1% of its label claim for melatonin.

Vitamin B12:

>Overall, vitamin B12 measurements in this batch analysis ranged from 515 mcg
to 6990 mcg per serving, deviating from label claims by an average of 27%. 3
products also recorded vitamin B6 and/or vitamin B9. 9 of the 13 products
recorded more vitamin B12 than claimed, with one product recording as much as
74% of its label claim for vitamin B12. All products passed heavy metal
screenings, and recorded vitamin B12 levels considered to be safe by the
Institute of Medicine (IOM)1.

------
cjCamel
Anecdotal I know, but I've heard of a couple of different areas where a a
medical professional recommends Vitamin D supplements to their patient.

Someone I know has been told to take vitamin D to help manage relapsing
remitting multiple sclerosis[1]

Another person has been recommended vitamin D to help with conception.

Seems to pop up all over the place.

[1] [https://www.mssociety.org.uk/ms-research/emerging-
areas/vita...](https://www.mssociety.org.uk/ms-research/emerging-
areas/vitamin-d)

~~~
TheSpiceIsLife
Henry Osieki in the 9th edition of his book _The Nutrient Bible_ factors
increasing demand for Vitamin D include:

 _alcohol, autoimmune reactive arthritis, bile problems, cancer (breast,
prostate, colon, and skin). Crohn 's disease, cystic fibrosis, elderly
individuals, hypoparathyroidism, intestinal disorders, insulin dependent
diabetes, kidney disorders, lack of exposure to sun, mineral oil intake
multiple sclerosis, obesity pancreatic disease, pregnancy, rickets,
schizophrenia, smog exposure, ulcerative colitis, use of anti convulsants e.g.
phenytoin and phenobarbital, steroid medication, vegetarianism._

Functions facilitated: _anti-proliferative effect - osteosarcoma, melanoma,
colon and breast cancer, apoptosis, anti-inflammatory action, blood clotting,
calcium and phosphate absorption and regulation, cofactor in synthesis of heat
shock proteins, differentiates leukaemia cells and induces apoptosis, heart
and muscle action, helps induce monocyte conversion to macrophages, increases
bone strength, induces apoptosis in breast and prostate cancer, increases
neurotrophic factor synthesis (NGF, GDNF, NF-3), increases the activity of
tyrosine hydroxylase and choline acetyltransferase, increases neural
glutathione levels, inhibits iNOS and TFN - alpha activity, immune-regulating
properties, mineralisation of bone and teeth potent anti-proliferative agent
in the colon, protects against neurotoxicity associated with ischaemia,
reduces the risk of colorectal and prostate cancer, regulates cellular
differentiation in intestinal cells, regulates or inhibits T-cell mediated
immune response, regulation of calcium and phosphorous metabolism, selectively
reduces interleukin 2 levels and proliferation of T cells, stimulates
polyamine, stimulator of ornithine decarboxylase and spermidine acetyl
transferase._

------
urlgrey
The USDA partnered with industry to develop a process for increasing Vitamin D
levels in mushrooms by simply exposing them to ultraviolet light.

Monterey Mushrooms has a video showing how this step was added to the
packaging process:

[http://www.montereymushrooms.com/nutrition/mushrooms-with-
vi...](http://www.montereymushrooms.com/nutrition/mushrooms-with-vitamin-d/)

------
jazzy1990
Interesting admission. There's been recognition of subclinical vitamin D
deficiencies for years in the professional athlete community, a segment of the
population at higher risk of bone and tissue disorders:

[http://journals.lww.com/cjsportsmed/Abstract/2010/09000/High...](http://journals.lww.com/cjsportsmed/Abstract/2010/09000/High_Prevalence_of_Vitamin_D_Insufficiency_in.9.aspx)
[http://journals.humankinetics.com/doi/abs/10.1123/ijsnem.18....](http://journals.humankinetics.com/doi/abs/10.1123/ijsnem.18.2.204)

There is no reason not to get tested given how easy it is to order online:
[https://www.accesalabs.com/Vitamin-D-
Test](https://www.accesalabs.com/Vitamin-D-Test)

I've tried out a handful of supplements for Vitamin D but haven't landed on a
good one. Has anyone tested, tried specific supplements, and then retested and
documented results?

------
JustSomeNobody
This makes it sound impossible for some people to get enough vitamin D from
sun and food without supplements. If you're fair skinned and living in
northern climates, you'll be deficient even with a healthy diet given that you
can't be out in the sun that long without burning. Is the human body that
defective?

~~~
PacketPaul
Wouldn’t it be if you are dark skinned not faired skin?

~~~
JustSomeNobody
This is true, yes. But really both have issues. It takes much longer in the
sun for a dark skinned person to get enough exposure to produce a healthy
amount of D. But the fair skinned person burns readily, so they can't stay in
the sun long without protection which would inhibit getting enough sun.

------
INTPenis
Living in scandinavia I've taken vitamin D every winter. But lately started
taking it all year.

I've been sloppy and it seems to coincide with periods of poor energy and a
bad mood.

I'm not sure if the energy and mood precede the drop in vitamin use or vice
versa. But either way I think it's good to supplement if you live up north.

------
macawfish
If you're looking for a better way to get vitamin D from supplements, try
drops instead of pills. Each drop contains ~1000 IU, so you could get around
40,000 IU with just a dropper-full... For most of us, a week's worth of 40,000
IU/day could really be a boost.

"Taking 50,000 international units (IU) a day of vitamin D for several months
has been shown to cause toxicity. This level is many times higher than the
Recommended Dietary Allowance (RDA) for most adults of 600 IU of vitamin D a
day.Feb 5, 2015" ([https://www.mayoclinic.org/healthy-lifestyle/nutrition-
and-h...](https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-
eating/expert-answers/vitamin-d-toxicity/faq-20058108))

~~~
macawfish
I'm remembering when I did this, I made sure to take epsom salt baths to
absorb magnesium!

------
timewarrior
One point of caution:

Anyone who takes Vitamin D supplement, make sure you take 25-Hydroxy
(Calcifediol) and not the active form - 1,25 dihydroxy (Calcitriol).

Active form has severe side effects and is not supposed to be used for
supplementation unless in you have kidney problem which prevent metabolizing
25-Hydroxy.

~~~
theprotocol
I thought all D2 and D3 supplements would be ergocalciferol and
cholecalciferol, respectively, while calcitriol is what gets tested to assess
blood levels. Do any supplements actually contain calcitriol?

~~~
timewarrior
Medical system in India is a mess of kickbacks. A Doctor gave my cousin a
prescription of Calcitriol because it was much more expensive. Led to major
side effects which went away as soon as it was stopped.

Supplements don't have it. However that warning was for someone who goes out
of way to acquire Calcitriol.

------
sitkack
One of the many great videos on the subject D is for Debacle - The Crucial
Story of Vitamin D and Human Health,
[https://www.youtube.com/watch?v=v3pK0dccQ38](https://www.youtube.com/watch?v=v3pK0dccQ38)

------
richardknop
I always wondered about this. Since I was very young, let's say after age 14
or so I rarely travelled for summer vacation and was living in Europe and had
almost no vitamin D from sunlight (working as software engineer and being a
nerd so all my hobbies were indoors).

I have always felt like I missed having a good time at a beach while sun was
shining (I remember it from family vacations when I was very young). Since
then I have spent couple of months in a country near equator and gotten lots
of (hours per day) sunlight. I feel healthier and happier now.

I also used to have deficiency of vitamin B when I was very young. I remember
I had to eat lots of fish oil to replenish my B complex (recommended by my
doctor).

------
hollander
Several years ago I read an article on Facebook about vitamin D, and because I
was in pain and tried many things like this, I read more about it, and started
using 2000 IU daily. In about two weeks I felt a lot better. Later that year I
was on holiday in the mediterrenean and noticed how much better I felt after a
morning in the sun. This made me decide to take even more, so I increased use
to 6000 IU/d, and I felt even better.

Several weeks ago I had my blood tested, and I came out under 100nmol, which
shocked me. I changed pills immediately, and am going to test again. I want
levels to be around 120, so I'm going to test once again. I'm going to call my
docter right now in fact.

~~~
macawfish
I recommend 1000 IU drops. They contain 1000 IU in a single drop, literally.
You can get them off the shelf at my local health foods co-op. I've taken
40,000 IU before in a single day (I read that was a safe upper limit for most
people). It felt amazing. It also helped me process built up emotions from
winter darkness and depression. That day I took 40000IU I literally wept, then
felt relief like none other, and a lightness of being.

Also, by the way, people under stress might appreciate some vitamin B complex.
There's a reason why they put vitamin B in those 5 hour energy drinks: it
helps our bodies cope with the stress of that much caffeine.

~~~
hollander
Be careful with that kind of dose! To compensate for insufficiency, it's
totally OK, but I wouldn't take it daily. You may start suffering from
calcification of the bones. This cannot be undone.

~~~
macawfish
Its good to be cautious. I did some research to come up with this upper limit
as an amount to take on a given day, and also wouldn't be worried about taking
this daily for a week since I live in Minnesota and am chronically deficient.

"Taking 50,000 international units (IU) a day of vitamin D for several months
has been shown to cause toxicity. This level is many times higher than the
Recommended Dietary Allowance (RDA) for most adults of 600 IU of vitamin D a
day.Feb 5, 2015" ([https://www.mayoclinic.org/healthy-lifestyle/nutrition-
and-h...](https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...))

------
pascalxus
I read another post somewhere that said all you need is 12 minutes of direct
sunlight to maximize your Vitamin D intake. It's because your body can only
absorb so much vitamin D at one time, from the Sun.

As for food products, there aren't that many natural sources of vitamin D.
Milk is fortified with vitamin D but doesn't come with it naturally.

Given how few sources of vitamin D there are:
[http://www.whfoods.com/genpage.php?tname=nutrient&dbid=110](http://www.whfoods.com/genpage.php?tname=nutrient&dbid=110)
I don't see how our species could have evolved to depend on vitamin D (other
than being outdoors).

~~~
drzaiusapelord
It drives me crazy that popular brands of soy and almond milk don't have
vitamin D. I've long moved off real milk because its really calories dense and
gives me gas. Now I'm missing out on one of the few easy sources of vitamin d.

------
mattferderer
I found the podcast Science Vs very helpful in understanding this topic -
[https://gimletmedia.com/episode/vitamins-supplements-
worth/](https://gimletmedia.com/episode/vitamins-supplements-worth/)

I was recommended Vitamin D by the wife of a Chiropractor. I do 2000IU
somewhat daily to every other day in the winter & 5000IU if I feel a cold
coming on with some extra zinc. This has made a significant improvement in my
ability to fend off colds. That said, I do try to exercise a few times a week
& eat as reasonably healthy as one can do in the far north midwest of America.

------
serbrech
For Vitamin D 1IU is 0.025mcg. 8000IU = 200mcg My box of vitamin shows a
Vitamin D3 content on 5mcg/pill (noted as 100% of recommended daily intake).
Time to change pill I guess...

~~~
dbeardsl
Off by a factor of 10.

0.025mcg * 8000 = 20mcg

~~~
serbrech
no... 200 is correct.

------
sharpenthesaw
This is fake news. I'll explain why I think so. Please counter me if I'm
wrong.

>>This piece of news is a literal "copy-paste" of the abstract of the article
"Big Vitamin D Mistake - BVDM"

BVDM is an article published by a Greek group. About the population from
Finland.

BVDM has 2 premises and 2 conclusions.

>Premise 1: There is a correlation (not causation) reported recently in
Finland of country-wide vit. D supplementation and lower Diabetes Mellitus
type 1 incidence. >Premise 2: There was a study published in America (Meta
Analysis of All Cause Mortality and Vitamin D - MAACVD) that investigated
deaths that had the lab values of vitamin D available. The main finding of the
study was: Vit. D levels of >30ng/mL is probably better than <9ng/mL,
correlated with a lower risk of death (hazard ratio of 1.6 to 2.2).*

THESE ARE THE PREMISES AND NO MORE. Here are their magical conclusions:

>Conclusion 1: The right level of vitamin D is 100ng/mL. This is apparently
extrapolated from a subgroup analysis in MAACVD. I find this extrapolation
shocking because: 1- this finding wasn't considered significant enough to be
published in the abstract by the original American group. 2- subgroup analyses
shouldn't be extrapolated. >Conclusion 2: in order to make sure everyone gets
this alleged "correct vit. D levels", here are the doses of supplementation
that everyone should get.

>> As you can see, the conclusions are far outside the realm of possibilities
offered by the premises. What the Greek authors did was nitpick a couple of
minor points in some random published studies and synthesize them into a
magical conclusion of how much more Vit D everyone should take (more than 3x
the current recommended amount in some ages).

This is sensationalism. I'm sorry to see such poor material to be presented as
science by "scientists" and "scientific journals".

>>Please correct me if I'm wrong.

*PS: I wasn't able to read the MAACVD full article, it wasn't free online. In these kinds of articles, the axis of the study is presented in the abstract, and the most significant findings are never left out. If someone has access to the full text, please share it with me and this forum.

------
sliverstorm
Anybody have tips on balancing all the cofactors? You need other things to
absorb & use the vitamin D. Some kind of multivitamin that focused only on D
and its cofactors might be handy, without going whole-hog to the "everything"
multivitamin popular today.

------
matco11
Vitamin D and Alzheimer’s
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153851/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4153851/)

------
OldSchoolJohnny
The Vitamin D council page answers nearly every question I've seen in these
posts: [https://www.vitamindcouncil.org/](https://www.vitamindcouncil.org/)

------
tgb
Is it standard for medical papers to write values with four significant
figures when they appear to have less than one significant figure worth of
precision? This is an actual question.

~~~
Sean1708
Are you talking about the abstract or is there something in the actual paper
you're talking about? Because I can't personally see anything in the abstract
to suggest that the values quoted to 4 s.f. only have 1 s.f. of precision.

~~~
tgb
Yes, the abstract. One sentence cites a result suggesting that 8895 IU/d is
necessary to reach >= 50nmol/L and the next another that 6201 IU/d is
necessary to reach 75 nmol/L. Clearly these aren't compatible to even 1
significant figure. Now, of course this is a matter of accuracy and not of
precision, but do you really believe someone's 4 sig figs of precision is at
all justified when they disagree with another person's 4 sig figs to such an
extent? It's possible, I guess! But I'm betting if you look at the original
study you only have 1 or maybe 2 significant figures that are actually
justified.

Look further at the paper where the 8895 number comes from [1]. That's the
only number reported to more than 2 sig figs in the paper and comes in this
context [emphasis mine]: "It also _estimated_ that 8895 IU of vitamin D per
day may be needed to accomplish that 97.5% of individuals achieve serum
25(OH)D values of 50 nmol/L or more. As this dose is far beyond the range of
studied doses, _caution is warranted when interpreting this estimate_.
Regardless, the _very high estimate illustrates_ that the dose is well in
excess of the current RDA of 600 IU per day and the tolerable upper intake of
4000 IU per day [1]." The two figures don't even show half the range needed to
see this value and make it pretty clear that this is a laughable amount of
precision to report. To make this clear: the value reported is the intercept
of the dashed red line with the 50nmol/L line in the second figure -- which
has been extrapolated out to a value almost _three times as large as the
highest dose used in any experiment_. And the extrapolation is done on a curve
that is getting very close to level at that point so even a _minor_ error in
dose response would cause a large error in reported dose. Frankly, after
looking at this, I don't think the originally posted article should have
quoted this number in its abstract - the point of this paper seems to be to
show that the standard value of 600 IU/day is unsupported form the data, not
to suggest that their 8895 IU/day is well supported.

Consider the most well-studied nutritional number we ever see: the daily
caloric intake! It's never given more than 2 sig figs and often just 1! And
this study is making the argument that the daily recommendations for this are
off by a factor of 10x. It'll take a lot to convince me that any number in
nutrition can be reported to 4 significant figures, and even then I expect
that it would be useless since inter-person variation is going to cause at
least a 1% difference (probably more like 25% differences like calories just
for men/women differences).

[1]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4210929/)

------
k3a
I think that vitamin D defficiency may have contributed to start of my
Multiple Sclerosis! I used to sit mostly inside all summer programming. So be
careful.

------
majani
Is this specific to North America? As someone who lives along the equator, I
think it's impossible to get too little sun exposure in these parts.

~~~
adventured
The study was about Finland. Scandinavia and northern countries broadly often
have a variety of bad health effects from very low VitD levels (including eg
very high rates of multiple sclerosis). Norway, Denmark, Sweden, Canada, UK,
Germany are among the nations with the highest rates of multiple sclerosis,
heavily due to their low VitD.

If you don't get enough sun (a minority of people anywhere on the planet do or
can), Vitamin D can be an important supplement no matter where you live. It's
well worth it to have a simple blood test done to get your levels checked, if
you can at some point, just to know where you stand.

------
robg
D3 is the more active form that's more readily absorbed. I've found the
Metagenics brand to be the best.

------
justin_d
Anyone who thinks they are D deficient should just go to the doctor and get
your blood tested.

------
debacle
> 8895 IU/d

This is double what I'm taking. The US RDA is 1/10th of this amount.

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ProblemFactory
Yes, that's the argument in the article: that the RDA is far too low.

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dharma1
How do you get your levels checked in the UK if you have private insurance?

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longwave
I was just looking this up after reading this article and discovered that an
NHS lab can send you a test kit in the post for £28, which will likely be
cheaper than any private option.

[http://www.vitamindtest.org.uk/](http://www.vitamindtest.org.uk/)

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dharma1
thanks!

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amrx101
One con of being in a Tropical country is that you don't have to worry about
your Vitamin D intake. The sun roasts you every year in the pre Monsoon heat.

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tastythrowaway
so does that mean we need more or less vitamin D?

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spuz
More; a lot more.

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guelo
This is one of the reasons I hate dermatologist's panic against sun exposure.
Vitamin D deficiency kills way more people than skin cancer.

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mohaine
My dermatologist actually told me to get more sun, but then I have psoriasis.

I believe his exact recommendation was one beach vacation every early Feb.

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tathougies
Does insurance pay for that? :)

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trhway
not to mention apparent connection to autism. Best example - Somali immigrant
populations concentrated in Sweden and Minnesota have unnaturally high child
autism rates and extremely low vitamin D levels (very dark skin, weak Sun, a
lot of clothes covering almost the whole body most of the year due to the cold
climate). Another Swedish study found, though much smaller effect, uptick in
autism rates among children whose 3rd trimester, when the brain develops the
fastest, fell onto the winter.

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basicplus2
Sufficient vitamin D is gained primarily from Sun exposure..

typically between 10am and 2pm, I have read that at certain latitudes and
times of year the required window is considerably less but cannot find a
reference.

[http://www.return2health.net/articles/does-vitamin-d-
really-...](http://www.return2health.net/articles/does-vitamin-d-really-come-
from-the-sun/)

~~~
tathougies
This is a very caucasian centric viewpoint.

The fact is that if you live in higher latitudes and have dark skin, you
physically cannot absorb enough vitamin D from sunlight during the winter
months. While it is physically possible during the summer, it is not practical
to spend hours sunbathing.

~~~
basicplus2
That's a very coloured centric viewpoint.

The fact is that the majority of people of planet earth can go out in the
sunshine at the right time of day and get 80-90% the vitamin D they need and
get the rest from a balanced diet.

~~~
tathougies
No that is not true at all. In today's world people of all races are living
everywhere, so we should give recommendations based off a person's individual
health. It is simply not true that a brown skinned person can absorb enough
vitamin D from the sun in the northern latitudes.

I said the above viewpoint was caucasian centric because it assumed that
everyone could get enough vitamin D from the sun. My response is not
'coloured'-centric because I did not say that no one could get enough from the
sun, only that your absorption depends on your skin color. My response was not
a generalization, unlike the comment I replied to.

