
Vitamin D, part 2: Shannon's story - usefulcat
https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-story?postId=5f39453f8d01fe00170023fe
======
orthopodvt
While hypervitaminosis D is a real syndrome, as evidenced by this story, low
Vitamin D levels are endemic in temperate and northern latitudes. We did a
study several years ago ( Vitamin D Status in an Elective Orthopedic Surgical
Population. Foot Ankle Int. 2016 Feb;37(2):186-91. doi:
10.1177/1071100715609054) in Vermont among healthy folks who were going to get
surgery and roughly 2/3 had low vitamin D levels (<30ng). Low vitamin D is a
significant risk factor for fractures, such as hip fractures in the elderly
which is a major cause of mortality. So please don't interpret this story as a
reason to avoid any vitamin D supplementation. 1-2000 IU/day has been shown to
be safe with long term use, but if you have any questions, you should
absolutely talk with your primary care provider. PS - Yes, I am a practicing
physician.

~~~
devaboone
I'm the physician who wrote the article. And I agree with you. Vitamin D
deficiency is a problem because it leads to bone loss (see part 1:
[https://www.devaboone.com/post/vitamin-d-part-1-back-to-
basi...](https://www.devaboone.com/post/vitamin-d-part-1-back-to-basics)). And
Vitamin D supplements can be very helpful for those with a deficiency. The
point that I am trying to make is that Vitamin D should not be thought of as a
dietary supplement. I am seeing more and more people with high calcium levels
from being on high-dose Vitamin D. If you treat Vitamin D like the steroid
hormone that it is, you will treat it like a medicine, and not take outrageous
doses because someone online suggested it. At least, that's what I'm trying to
get across.

~~~
bobobob420
I walk for 30 minutes a day in direct sunlight. If I do this for a year (been
5 months so far) do I not need to worry about vitamin d intake? I am also a
healthy young male in my 20’s

~~~
rnd33
As others have pointed out, it depends on time of year and where you live. Far
north, e.g. Canada, the U.K, Scandinavia the sun won't give you any Vitamin D
at all for roughly six months of the year.

~~~
elliekelly
I’ve been using the DMinder app (not affiliated in any way and it’s totally
free) to estimate how much vitamin D I’ve been getting. You input how overcast
it is and what percent of your skin is exposed and then it uses your skin tone
(input at setup), latitude, altitude, and time of day and it’ll track a rough
estimate of how much vitamin D you’ve produced while you’re outside.

There’s also “Quick and Easy Screening for Vitamin D Deficiency in Adults”[1]
which has a quick and dirty formula in Table 2 to help assess your risk of
deficiency without a blood test.

[1][https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4998626/pdf/med...](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4998626/pdf/medi-95-e2783.pdf)

~~~
nytgop77
is exposed amount of skin an input?

------
DoreenMichele
_After a full workup, the doctors had no explanation, so they resorted to what
doctors often reach for when confronted with mystery ailments: psychiatric
illness._

Yeah. This is a big problem for people with serious and complicated health
issues. They are all too often told "It must be in your head" the subtext
being "If it were real, I, a super smart doctor type, would be able to figure
it out already." It's ugly stuff and it ruins lives.

Also, the lady was prescribed vitamin D and then took it without adjusting the
dosage or having a follow-up about it for _5 years_. This is a big problem as
well. Doctors all too often don't follow up with patients and this is probably
in part because of our issues in the US with how we pay for stuff and so on.
But it was also a problem for some things when I was a military wife and could
see a doctor for free.

I am a writer by trade and I have a serious medical condition. I'm glad to see
this piece and I'm glad to see Deva Boone posting on HN, but I will suggest
that statements like "Vitamin D is a medication" don't constitute good
communication.

The latter part of the piece makes it clear what is intended by that, but it's
not currently classified as a medication and I think it is generally more
helpful to try to educate people that "life is chemistry" and there is no
clear cut demarcation between "drugs" and "not drugs." Sometimes the
difference boils down to dosage.

There are lots of things available in small quantities in food items that are
"drugs" if you take a large enough amount in one shot and are "drugs" if
prescribed in pill form that are "food" when part of your diet. And we need to
get a lot savvier about things like that.

Hopefully, this is taken as helpful feedback and not an ugly attack. It is
intended as the former and not the latter.

~~~
devaboone
Thanks! It is very helpful. These are great points. I actually tell my
patients that _every_ supplement or vitamin should be thought of as a
medication. I had written "should be thought of" in the article and then just
switched to "is a medication" to make the sentence simpler. It probably
changed the meaning too much. It's been very interesting to read the responses
on here, and I appreciate the feedback.

~~~
tinco
What do you think of the idea that doctors don't follow up on their patients?
I have a friend who is a physician that can not practice because of medical
reasons, he is now experimenting with a business where he reviews peoples
medical dossiers to check whether their doctors have missed anything that
could be important.

He's got crazy stories of doctors skimming dossiers because of time
constraints. A poignant case he described was where a doctor did not notice
his patient was 100kg lighter than the last time she visited. How do you miss
you've got only a third of the patient you had before he exclaimed when he
told me this story.

~~~
DoreenMichele
When I worked at Aflac, there was a quadruplegic former surgeon who came in
like once a week and reviewed records for the really hard things that we, in
claims, were having trouble figuring out. Because he was quadruplegic, someone
brought him upstairs on the elevator and you had to print your entire claim
out and someone turned pages for him. He only read it and made a
determination. I got to see it firsthand once when one of my claims went to
him.

I run a google group called Health Techies and your physician friend is
welcome to join, if he is interested. It doesn't see much activity, but, you
know, sometimes you get enough people and conversation breaks out, at long
last. Or new people show up, have questions, and then conversation happens.
Voila!

------
Cactus2018
Hi Deva, what do you think about the _Vitamin D Hammer_?

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4463890/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4463890/)

> A colleague of mine and I have introduced vitamin D at doses that have
> achieved greater than 100 nmol/L in most of our patients for the past number
> of years, and we now see very few patients in our clinics with the flu or
> influenzalike illness. In those patients who do have influenza, we have
> treated them with the vitamin D hammer, as coined by my colleague. This is a
> 1-time 50 000 IU dose of vitamin D3 or 10 000 IU 3 times daily for 2 to 3
> days. The results are dramatic, with complete resolution of symptoms in 48
> to 72 hours. One-time doses of vitamin D at this level have been used safely
> and have never been shown to be toxic.8 We urgently need a study of this
> intervention.

~~~
shajznnckfke
Doesn’t the flu usually resolve within a few days without a vitamin D hammer?
Did they do a controlled blinded study to determine whether it made a
difference?

~~~
majkinetor
It depends. It can take from few days to few weeks. Also, there can be serious
side effects for life.

~~~
shajznnckfke
I agree, there’s a diversity of possible outcomes. I think case reports of flu
recovery after a treatment are of limited value absent a quantitative analysis
showing the treatment had some effect.

------
jgilias
We really need to change the whole medicine paradigm from checking when
something is wrong and trying to fix that to doing comprehensive checks
regularly and adjusting the necessary supplementation and preventive
treatments upfront. I think more and more people are doing this on their own,
but in my experience it's still a small minority and far from being seen as
essential.

~~~
electriclove
I think we need to enable technology so people can do these checks
themselves/at home. It seems we are holding back the tech because we are
afraid of what people will do with the information.

~~~
DoreenMichele
Tech is cool and all, but this can be done much more simply with just reading
a lot and keeping a journal and that sort of the thing.

The real sticking point is the minute you know "too much" about the impact
things have on the body and try to engage in discussion, someone will have a
cow about how you are "practicing medicine without a license" or something.

The problem is that any exercise of real power will get someone's hackles up,
even if that power is just a case of "knowledge is power" and medical/health
stuff is a super touchy topic for a long list of reasons.

~~~
jgilias
Respectfully, there is a reason why one must have a license to practice
medicine. It's simply too easy to kill people inadvertently. I guess that's
fine if the unlicensed doctor is the only patient.

But then, I do agree that a license doesn't necessarily guarantee competence.
A GP being interested in and keeping track of the latest research on
nutrition, longevity, etc, would be worth their weight in platinum.

~~~
DoreenMichele
You have completely and totally missed my point while simultaneously sort of
making it for me, which I imagine you will fail to see.

------
fossuser
Part 1: [https://www.devaboone.com/post/vitamin-d-part-1-back-to-
basi...](https://www.devaboone.com/post/vitamin-d-part-1-back-to-basics)

HN:
[https://news.ycombinator.com/item?id=24138590](https://news.ycombinator.com/item?id=24138590)

It's nice to see a real blog post about this from a real doctor. There's so
much misinformation and terrible writing about supplements online, thanks for
writing this.

~~~
KerryJones
I agree about posts from a real doctor, but this is using an anecdotal case as
a basis to shift a definition of a vitamin? That seems pretty poor form for
someone in the scientific community. We should be shown stats of of likelihood
of this happening compared with the opposite, studies, ways it can be safe and
not safe (such as with K2, with calcium supplements, etc.)

This was not a refreshing read from my standpoint, just feeding the internet
echo-chamber.

~~~
DoreenMichele
Vitamin D is not actually a vitamin and that is easily googled. You don't have
to be a physician to know that.

She is absolutely correct that it is a steroid, not a vitamin. Vitamins are
things your body cannot manufacture. Vitamin D is something we can
manufacture.

She's apparently new to blogging and medical blogging is hard and I'm sure she
will get better at effectively communicating what she wants to say with a
little practice.

I agree with you that she shouldn't have stated "It is a medication" and I
have stated that elsewhere and she clarified why she chose such phrasing and
it's a somewhat minor nitpick because the latter part of the article does make
it clear what she is trying to get at.

~~~
devaboone
Thanks! Yes, I am very new to this. Hoping that by continuing to write, I'll
get better. The comments on here are great for helping me understand how
things are interpreted.

~~~
DoreenMichele
You will and you've actually been really well received. I wouldn't worry about
the occasional negative remark. Those are going to happen and other people can
often figure out that it's someone being weirdly pendantic or whatever.

Bill Gates has said something about "your unhappiest customers are your best
source of learning." I like to view big negative reactions to my writing in
that light and help me up my game for future pieces.

There are no soft launches and this is all grist for the mill.

------
mitko
Few months ago I head how vitamin D is associated with COVID-19 outcomes and
went into a rabbit hole to find more information about wtf is Vitamin D, and
how our bodies use it/need it.

There are two videos I found particularly informative.

1\.
[https://www.youtube.com/watch?v=91eDzM0qiJM](https://www.youtube.com/watch?v=91eDzM0qiJM)

Cost/Benefit of Optimal Health with Sunshine Vitamin D

William B. Grant, PhD

2015

2\.
[https://www.youtube.com/watch?v=v3pK0dccQ38](https://www.youtube.com/watch?v=v3pK0dccQ38)

D is for Debacle - The Crucial Story of Vitamin D and Human Health

Ivor Cummins BE(Chem), CEng MIEI

2014

------
floatingatoll
The basic rule of thumb I will now use for vitamin D, as a result of this
article, will be the same as any other hormone: to commit to having blood
hormone levels tested at least twice, once prior to medication (to confirm
necessity and safety) and once after every 6-12 weeks of medication (ramping
up through annually, once the dose is calibrated, until treatment ends).

If you don’t test it before, you have no idea whether you’re treating anything
or not. If you don’t test it after, you have no idea whether you’re taking too
little or too much. If you don’t test it every couple months at first, you
won’t be able to calibrate your dosage levels properly.

That’s a lot of blood tests, but the alternative is risking wasting your time
and money, or wasting your health, time, and money, on potentially useless or
harmful dosages. And if you don’t think it’s worth a blood test, you probably
ought not take it.

(I do not currently need to take vitamin D, thanks blood tests!)

------
look_lookatme
It is my understanding that vitamin K2 should be taken with vitamin D in order
to mitigate calcium overload. I do not know what the appropriate dosages
between the two are, however, and I just pop one with the other every other
day.

~~~
devaboone
Vitamin K2 is definitely an essential vitamin for bone health and calcium
regulation, but it won't counteract high dose Vitamin D. If you are on so much
Vitamin D that your calcium is elevated (meaning, you are at a toxic dose of
Vitamin D), Vitamin K2 is not going to help. The best thing to do is actually
check your Vitamin D levels if you are planning on staying on high dose
Vitamin D.

~~~
refresher
Any ballmark suggested amount of K2 per 1000 IU of D? The supplement I'm
currently taking is 100mcg of D3 with 75mcg of MK7 K2.

------
tiborsaas
It's interesting to note that Vitamin D is in the center of attention due its
link with COVID-19:

[https://www.researchsquare.com/article/rs-21211/v1](https://www.researchsquare.com/article/rs-21211/v1)

~~~
ljhsiung
I think the jury's still out on whether the link is causal or correlated, and
that study in particular is under controversy.

Personally, I think its just because higher Vitamin D levels mean you
generally go out more, which is associated with general fitness levels.

~~~
collyw
I am leaning towards the opposite conclusion based on three things I have
heard.

I have heard vitamin D described as a "modulator for the immune system" (isn't
the problem with Covid that your immune system is overreacting?). Also I know
that its a factor in Multiple Sclerosis, which is an autoimmune disease. Also
things like flu infect / kill more people in winter- when people will be
getting less sun, and so have less vitamin D.

------
kpfleger
Terrible piece. First off, the majority of people with D levels of ~80ng/ml
are fine, even quite healthy. Her problem was too much calcium, which is
related but they (at least not in the article) don't address what her calcium
intake was. Probably she was supplementing that too if the original reason for
her supplementation was osteopenia. It's not clear if she would have had any
problems if she had just dropped her calcium to low-normal intake. Quite a
large fraction of Americans consume too much dairy.

Article that cherry pick a single example are terrible when they pick the
example that is 100x less common than the other side of the story. 35-40% of
the US has D < 20ng/ml. That's probably 100x greater than the number that have
D >= this woman's levels (~80) and probably only 1% of folks who have that
level have any kind of medical issue with it the way she did.

I completely disagree with the idea that D should be thought of as a
medication in the sense of being careful with it. The problem currently is not
enough care to make sure to get enough. 19 organizations (all the big
important ones) consider 4000 IU/day of vitamin D to be a safe intake without
the need to consult a doctor. The Endocrine Society and a few other orgs
consider 10,000 IU/day safe. At the level of 5000 IU/day that she was taking,
a very large % of people will remain clinically deficient. Many, many more
than will have any kind of adverse issues.

The right dose for society to advocate as a default is not the dose that
causes huge amount of harm on the low end only to avoid any kind of harm on
the high end at all. That kind of asymmetric health optimization is poor
public policy. But it's the way doctors think. Cover my ass and make sure to
do no harm. The Hippocratic oath is a terrible way to optimize net health of
society and it's unfortunate it has become entrenched in public health, not
just the actions of individual doctors.

~~~
gnicholas
I thought it was a very helpful article — and it made clear that what happened
to this patient will not necessarily happen to everyone. It informed me that
vitamin D is a hormone (I did not know that!), and that there are things to
monitor if you are taking a bunch of it. I have family members who take
calcium and vitamin D, and I will ask them if they monitor these things.

It would be bad if this article pretended this patient's experience was the
norm, but it didn't. It provided information about what can happen and
advocated for people being more circumspect about a particular
vitamin/hormone.

------
Alex3917
OK so the thesis of this piece is that you shouldn't give blanket advice about
what dosage of vitamins to take. But if you Google it, you would immediately
see that taking over 4,000 IU of vitamin D per day for extended periods can be
toxic. So in this case the woman would have actually benefited from taking the
blanket advice rather than taking the 'personalized' advice from her doctor;
had she been taking only 1,000 IU per day, I doubt she would have had this
issue.

~~~
devaboone
Unfortunately there are a lot of places online that will recommend 5000 units
a day or more. And at the store, one of the standard doses for Vit D is 5000
units. I have this dose in my medicine cabinet. And it's not a completely
unreasonable dose. Shannon actually did need 5000 units daily - just not for
five years. The problem is that no one knew to reconsider it, or look for
elevated calcium.

~~~
fossuser
Yeah and one of those places is definitely HN - I've seen crazy
recommendations here when it comes to supplements/nutrition.

I'd guess there will even be some in this thread.

------
mastre_
A bit over decade ago when I started running (& cycling) hardcore I had some
knee pain and started taking Glucosamine & Chondroitin supplements for it. It
seemed to work, maybe it was placebo effect, but regardless I was "sold" on
it. A year or so later I started getting hives all over my body. I was (and
am) quite healthy, and coupled with the fact that I'm not really allergic to
anything this took me by surprise. It got bad enough that I had allergy panels
done, which unfortunately came back with allergies to all sorts of things and
the docs put me on anti-allergy medication (Zyrtec, along with stronger Rx
only stuff). I was quite discouraged, esp when the docs told me that one can
become allergic to anything at any point in one's life, and I was slowly
starting to accept it. The Zyrtec seemed to help, not 100%, and I didn't seem
to have to take it regularly, so it wasn't the end of the world. Then, at one
point I took a 10 day trip and didn't take my supplements with me. The hives
went away. Thru the process of elimination I traced it down to the Glucosamine
& Chondroitin supplement. It's probably been a decade since I've been back to
my normal, non-allergic self. I still take Glucosamine & Chondroitin
supplements for a period of time at a time, but am keenly aware of not letting
things build up to toxic levels after this lesson learned.

~~~
Cactus2018
[https://www.mayoclinic.org/drugs-supplements-
glucosamine/art...](https://www.mayoclinic.org/drugs-supplements-
glucosamine/art-20362874)

> In supplement form, glucosamine is harvested from shells of shellfish or
> made in a lab.

The hives might be a shellfish allergy.

~~~
mastre_
> The hives might be a shellfish allergy.

I considered this too, but never had problems eating shellfish. Tho it's
possible that in higher quantities the allergens from shellfish were indeed
the cause.

------
magneticnorth
Is there a relatively easy way to check vitamin d levels, or does it require a
lab test and doctor's visit?

I live in a cloudy northern climate and tend to assume I have low vitamin d in
the winter (and a supplement has a noticeable improvement on my mood), but I
would love to actually track my levels and understand how much supplementation
I need to say in "normal" levels at different times of year.

~~~
Cactus2018
Recently there are a lot of "request lab test online" websites; ex.
[https://www.ultalabtests.com/Shop/Items/Item/Vitamin-D-25-Hy...](https://www.ultalabtests.com/Shop/Items/Item/Vitamin-D-25-Hydroxy-
Total-Immunoassay)

------
asperous
At first my reaction was this must have been a one-off case, usually I see D3
in bottles with 500IU, who is taking 10 vitamins thinking this is right?

But I looked it up and there are 5,000IU capsules being marketed now. That
seems like a problem. People are going to naturally expect 1-3 pills of
anything are safe. Dangerous design.

FDA does take complaints/reports, I wonder if enough people complained they
would pull the high dose pills.

~~~
KerryJones
I've talked to multiple nutritionists and they often recommend 5,000IU a day
-- we shouldn't be going off gut reaction. There are widespread surveys that
show high vitamin D3 deficiency and there are many more stories of people who
have taken this vitamin at that dose for years without problems.

The point is, we need more than stories. We need study and analysis, not a
random call to change the definition because of a story.

------
amanaplanacanal
Better just to get some sun. Your body will self regulate how much is produced
in your skin from the ultraviolet that reaches it. Just don’t stay out so long
you get burnt.

~~~
joncrane
I went on vacation in Costa Rica, leaving my Vitamin D pills at home, thinking
the same thing.

Not true! I had to shell out like $30 to buy imported Vitamin D tablets
because I could feel the positive effects of my Vitamin D supplementation
wearing off within 4 days.

And I had gotten enough sun to get a serious tan already.

People process sunlight and synthesize Vitamin D at different levels.

~~~
jmckib
Could that be in your head? Vitamin D lasts a long time in the body, seems
unlikely you'd be able to notice any difference after four days.

------
CoffeeDregs
First, this is not an argument against posting this post...

This is an excellent post (I've shared it on). It'd be a great service to the
HN community to do these as an AMA-type-thing. Deva is on here and is very
generous with her time but it'd certainly embiggen the impactyness to have a
"Deva will be on from 10AM-12PM PT on 2020-08-24 to answer questions. Not
medical advice, etc." and "Deva's out." sticky notes at the top.

[In which I suggest _someone else_ undertake an obligation for the
community... Aware of that. It's just lovely to have such a person/resource in
the community and it'd be good to set expectations ( __none __/ some) around
her involvement since people are dropping in questions and (I assume) hoping
for (free) advice/counsel.]

~~~
conorh
I'm sure Deva would be up for it, she does it for some patient groups she
works with on Facebook, but I'm not sure if Hacker News is a good place for
it? Also speaking as Deva's husband I think the kids and I would like to see
her at dinner more, joking (she is a regular attendee at dinner), but you
would not believe how much effort and time she puts into researching, thinking
about and working on these things (along with everything else she is doing).

------
throckmortra
I feel like I can't win either way. I had a vitamin D deficiency a few years
ago and it led to neurological problems and I thought (based on internet
advice, especially HN posts) that I should be taking 5000~ IU a day. I still
feel no closer to an answer as to the appropriate amount.

~~~
devaboone
This is a great point. Vitamin D deficiency causes problems, and should be
treated. 5000 units a day can be great for treating a deficiency - until you
are no longer deficient. The answer for you is checking your Vitamin D 25-OH
level. If it is still low (under around 30), then you may need the high dose.
If it is getting too high (above 60) then you need to back off. There isn't a
one-size-fits-all dose for everyone.

~~~
throckmortra
Is there a better/quicker way of checking these levels rather than going in
for a bloodwork panel? I feel like my natural Vitamin D intake can change
really dramatically based on the season. I worry that maybe I'm overdoing it
in the warmer months. I typically go in once a year for a physical and that's
the only time I ever see these levels.

------
joveian
One issue I found 3-4 years ago was that some common tests undercount D2 by
quite a bit (I forget if it was 20% just for D2 or I think it might have been
20% overall D2+D3 in some test samples). I found this because the test my
doctor ordered had a statement about using a different test if supplementing
with D2. A number of products (like soy milk) contain some amount of D2 so in
some cases low vitamin D might be due to inaccurate testing. I haven't checked
if the tests have improved in the last few years.

~~~
getpost
D2 is the active form in plants. In humans it must be converted to D3.

[https://www.healthline.com/nutrition/vitamin-d2-vs-d3#sectio...](https://www.healthline.com/nutrition/vitamin-d2-vs-d3#section1)

------
norswap
Seems factual, but raised my eyebrows a couple times. Comparing Vitamin D to
steroids is completely gratuitous. Sure, they're structurally similar, but so
are oxygen (O2) and Ozone (O3). Have you ever tried to breathe Ozone instead
of Oxygen?

From the previous article:

> Unfortunately, we do not have a full unified explanation for how Vitamin D
> deficiency could lead to the list of diseases that are associated with it.
> We know the correlations are there, and we can show that the Vitamin D
> molecule has an effect on multiple cells and organs.

So if you are deficient (as most adults are), you should take Vitamin D to
avoid those. It's irrelevant that we do not know pathways. This probably
suffers less confounders than other health issues, because Vitamin D comes
from the sun.

But in this article:

> A few readers have made comments like this: “I understand that the evidence
> for Vitamin D in healthy adults doesn’t really show a benefit, but I take
> Vitamin D because it probably won’t hurt me, and it might help.” This is a
> common sentiment regarding supplements, but not a statement that most people
> would make about metoprolol, or any prescribed medication.

It's hard to see how this sentiment isn't exactly correct, at least if you're
deficient. Remember, most people are, so if you don't go outdoors a whole lot,
you probably are.

I'm also surprised Vitamin K isn't mentioned. I take Vitamin D, but I've heard
the standard advice is to always take Vitamin K in addition, which helps to
regulate Calcium and avoid the issues described in this article.

------
radu_floricica
A bit disappointed. Anything has a one in a million chance of killing us. What
we know is that vitamin D yes, has a chance of hurting, and also has an orders
of magnitude higher chance of helping. I was hoping for more information about
how to make the risk trade-off, and what we got is an anecdote.

The general rule is to also take into consideration both magnitude of the
potential harm and its probability, in order to avoid a wipe-out (you can't
recover your losses if you're broke or dead). But even if we take this into
consideration, and take the anecdote in the article as a reference point for a
"bad case", it's still in the "no lasting harm" category. And very obviously
an outlier, since she showed symptoms while test results were in the green.

If anything, this confirms that as a population we should supplement more on
Vit D, and when unable to test Vit D levels, we should still chose in favor of
supplementation. If it were otherwise I'd have expected better arguments
against it.

I didn't update much after reading this. The upper limit is still pretty
common sense: don't use high dose supplementation daily for years without
testing. Very likely ok to use in any other scenarios: high doses like 50.000
per flu episode, or 1000 or so daily. Never mix sun and supplementation.

------
eagsalazar2
How do vitamin D levels decrease over time if you stop supplementing or stop
going outside?

For example, say I'm super active and outdoors every day, my D levels are
great. Then I get, say, Covid-19, and I stay inside for a week feeling icky.
If I'm not recovered yet, are my D levels still good? Or am I now at higher
risk for Covid complications because my D has decreased?

There are all sorts of questions that could be answered by understanding this
better. If I am outdoorsy and take a day to work inside on a project, should I
supplement that day? What if I am a tech worker who is inside most days but I
do 2-3 outdoor activities per week? Am I good? Or should I be supplementing?

If I take a D supplement and 2 hours later take a D test, does it matter? What
about when I first wake up and haven't been in the sun for 10 hours?

I have no idea the answer to any of these questions (as a tech worker who
supplements, goes outside for hikes/rides 2-3/week, and has a Vitamin D test
sitting on my self, wondering when I should take it...)

~~~
fauigerzigerk
According to my former GP, vitamin D can fall below recommended levels over
the winter months if you haven't stored up enough of it during the summer. So
it's a matter of months not days.

As I understand it, vitamin D first goes into the blood. Any excess is then
stored in your body fat and in your liver where it can last for months.

So I'm thinking that taking supplements right before a blood test could be a
bad idea. But that doesn't mean depletion of stored up vitamin D happens
within hours. It definitely does not.

------
0DHm2CxO7Lb3
Chris Masterjohn has an interesting talk called "Resolving the Vitamin D
Paradox" where his hypothesis is that vitamin D, A, and K all need to be
balanced for proper regulation of vitamin K dependent proteins.

[https://www.youtube.com/watch?v=9H7tbWVNrXQ](https://www.youtube.com/watch?v=9H7tbWVNrXQ)

------
_greim_
I've seen comments to the effect of "standing outside on a sunny day in a
bathing suit for five minutes is the equivalent of 10,000 IU vitamin D." No
idea if that's true, and obviously UV exposure has other risks, but strictly
speaking, could vitamin D ever be boosted to harmful levels by UV alone?

~~~
cpncrunch
Here is the study:

[https://pubmed.ncbi.nlm.nih.gov/20363523/](https://pubmed.ncbi.nlm.nih.gov/20363523/)

It would take roughly an hour per day of exposure to 25% of the skin in summer
midday sun to get 5000IU (depending on skin type and UV index).

The article seems to be conflating correlation with causation.

------
tedunangst
For reference, 5000 IU is 625% USDA DV. (Curiously, 5000 / 600 = 8.33, but
5000 IU bottles are labeled 625%.)

~~~
hammock
[https://www.sciencedaily.com/releases/2015/03/150317122458.h...](https://www.sciencedaily.com/releases/2015/03/150317122458.htm#:~:text=2-,Recommendation%20for%20vitamin%20D%20intake%20was%20miscalculated,far%20too%20low%2C%20experts%20say&text=Summary%3A,by%20a%20factor%20of%20ten).

------
noipv4
I use an app called D-Minder to check / control my sun exposure. In the summer
months I easily get 5000 IU after a 30 min session in the noon sun, approx
12pm. Anecdotally vitamin-D does help with my auto-immune, because I need to
take much less thyroid dosage (25mcg as opposed to 75mcg) to arrive at the
same TSH levels.

Higher D levels did make my teeth sensitive so I upped my Calcium and
Magnesium levels. I take CCM, calcium citrate malate which is absorbed more
easily than calcium carbonate. I also take Vitamin K2 as MK7 and drink Kefir
regularly.

------
y-c-o-m-b
I've been taking 5000IU per day for YEARS. I just recently started taking K2
100mcg every other day. I've seen countless family doctors and neurologists
over the years with this information, and none of them ever said it was high.
I live near Portland, OR where you don't see blue skies from November - March.
However I get abundant amounts of sun each day when the sun is out during
spring/summer/autumn. Getting tested is not an option right now (covid
mitigation), so should I taper back to maybe 5000IU every 3 days?

------
sinuhe69
I think it’s a crazy story. Which doctor on earth would prescribe a 5000 IU
vitamin D dosage daily without a specific treatment length? Because the
recommended dosage is just 400 IU daily and almost all medical sites warn
about high dosage above 4000 IU Vitamin D daily, I think the doctor who
prescribed a 5000 IU daily dosage without a specific treatment length was
plainly irresponsible or the patient was not followed the doctor's instruction
correctly, which is equally bad and irresponsible for one’s health.

------
IngvarLynn
Anecdotal datapoint: vitamin D provokes depression for me. Take 5000IU in the
morning and an episode is guaranteed in the next evening. Episode consists of
pretty bad mood and "inability to think" for the lack of better words. And it
builds up of course. After about a month of 10000IU daily I was on a brink of
suicide. Unfortunately I did no tests whatsoever. I've had zero psychiatric
issues before but I do have a fistful of medical conditions.

------
amai
Vitamin D has less to do with sun than you think. Low Vitamin D levels are
also common in Africa. So don't take Vitamin D just because you think you're
not outside long enough:

[https://theconversation.com/think-vitamin-d-deficiency-is-
no...](https://theconversation.com/think-vitamin-d-deficiency-is-not-common-
in-africa-think-again-140080)

~~~
kevinmchugh
The "What’s behind the deficiency" section seems to point to sunlight exposure
as a very important part of the equation. In particular: > As we found in the
study, urbanisation seems to be a major cause. People are spending more time
indoors. In contrast, Africans in rural settings have been reported to have
one of the highest levels of vitamin D in the world.

~~~
amai
That would be in contrast to the common knowledge that 15 min in the sun are
enough for a good Vitamin D level, especially 15 min in the African sun. I
simply can't imagine that you can live in Africa without getting enough sun.
That would mean that you basically have to stay underground all the time. I
believe there is a second factor (often overlooked) that causes low Vitamin D
level in the blood: Magnesium deficiency:
[https://pubmed.ncbi.nlm.nih.gov/30541089/](https://pubmed.ncbi.nlm.nih.gov/30541089/)

~~~
kevinmchugh
As your previous link mentioned, not all of Africa is equally sunny. But
really the difference is that people with darker skin need to spend more time
in the sun to get enough Vitamin D. At least one source says folks with very
dark skin need six times as much sunlight as those with very light skin. I've
seen 3 hours daily recommended before as well. It's going to be challenging
for an urban person at any latitude to get that much sunlight in a typical
day.

[https://health.usnews.com/wellness/articles/2018-07-18/how-m...](https://health.usnews.com/wellness/articles/2018-07-18/how-
much-time-in-the-sun-do-you-need-for-vitamin-d)

------
amai
Dai (2018): Magnesium status and supplementation influence vitamin D status
and metabolism: results from a randomized trial

[https://pubmed.ncbi.nlm.nih.gov/30541089/](https://pubmed.ncbi.nlm.nih.gov/30541089/)

"Our findings suggest that optimal magnesium status may be important for
optimizing 25(OH)D status. "

------
trulyrandom
Keeping your Vitamin D levels in check becomes even more of a challenge if
you're not normocalcemic. In my case, Vitamin D levels always turn out to be
almost unmeasurably low when I get bloodwork done. If I then supplement high
doses of Vitamin D in response to that, the level rises only slightly, and my
Calcium level goes up even more than it already is.

------
ameixaseca
Five _years_ taking 5000 UI daily. This goes on to show that short-term usage
is likely a benefit.

------
Jedd
For people living in the southern hemisphere, don't feel too smug about all
the comments that this only affects people 'in northern latitudes'.

What they mean is 'the northern parts of North America'.

If you're south of the equator by, say, 35-40 degrees or more - similar risks
& problems apply.

------
DNtBlVtHhYp
What’s your opinion on K2 + D3? Bone density against osteoporosis,
particularly on the elderly?

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5471136/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5471136/)

------
Gatsky
Yeah I noticed you can buy large doses of vitamin D in the USA. It is quite
cost-effective to get the 5000 or 10000 IU capsules and take one a week. In
Australia you can't usually get more than 1000 IU in a capsule at the normal
pharmacy.

------
chemmail
Seems to me that 5000 is just too much, and 400 daily recommended might be
low. Seems like between 1000-2000 is a sweat spot.

------
ping_pong
These articles are fantastic. Thank you for taking the time to educate us with
your knowledge and experience!

------
asjo
Raise your hand if you thought this was another one of Claude Shannon's many
tangents.

------
known
I'd suggest you first test vitamin levels and then take appropriate
supplements;

------
redlizard
Hopped on the last thread a little late and couldn't get a meaningful
discussion about this (Perhaps i'm just completely on the wrong foot):

Are these studies just showing that vitamin D is a good predictor of income
(because race is a good predictor of income)? Now that the US is starting to
have conversations about racial inequality, every time I see a hackernews or
reddit post on vitamin D I am asking myself that question. I have read several
studies that link low income to higher mortality rates across several
different diseases. [0]

And several other studies that link education levels (which are inherently
linked to childhood wealth levels) to worse mortality rates as well.[1]

There is a link between lower vitamin d levels and skin color, with an obvious
plausible explanation ( Melanin lowers skins ability to produce vitamin D).[2]

In the U.S. at least there is a strong link between income, education levels,
and skin color. [3]

While I am hopeful that ongoing research will help us understand the
mechanisms by which vitamin-D operates, I really worry that it is somehow a
very well dressed red-herring. One one hand a promised panacea: vitamin d
supplements, the other a complex economic and political problem that barely
anyone can comprehend or are even willing to engage with.

One of the more damning studies shows that vitamin d supplementation is good
enough to remove your deficiency, it has reproduced really poorly on any of
the other correlated health effects.[4]

Are there any studies that someone can link that would alleviate my concerns?
When these kind of population health studies are conducted (I am in no way
familiar with how they are actually done), how are factors like income
inequality and education level generally controlled for?

And an interesting article related to Vitamin-D health benefits that had a
slightly different take on causes for supposed benefits:
[https://www.outsideonline.com/2380751/sunscreen-sun-
exposure...](https://www.outsideonline.com/2380751/sunscreen-sun-exposure-
skin-cancer-science)

[0]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866586/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866586/)

[1]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435622/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4435622/)

[2]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946242/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946242/)

[3]
[https://journals.plos.org/plosone/article?id=10.1371/journal...](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0190640#sec014)

[4]
[https://www.nejm.org/doi/full/10.1056/NEJMoa1809944](https://www.nejm.org/doi/full/10.1056/NEJMoa1809944)

~~~
devaboone
Thanks for commenting. These are all great points. For a while I have thought
that Vitamin D just became the latest Vitamin C - are people on here old
enough to remember when Vitamin C was a miracle drug that treated and
prevented cancer? Fortunately you can expel excess Vitamin C much easier than
Vitamin D. In my next post on this I really want to go into the human trials.
The evidence for Vitamin D supplementation in the general population is just
not there. And yes, darker skin color is a risk for Vitamin D deficiency. And
the correlations that you mention are all real, which can partly explain the
correlations between low Vitamin D and health problems - and then explain why
supplementing doesn't seem to help. It's not the Vitamin D causing an
increased mortality - it's everything else that might be associated with low
Vitamin D and at the same time associated with mortality.

~~~
mrandish
Deva,

Thanks for your articles (P1 and P2) as well as your posts on HN. I'm happy to
hear there will be a Part 3. The topics you describe above will be of
interest. I'm a layperson who has read many of the recent papers on D3 and
have been supplementing 6k IU D3 with 100mg K2-mk7 (recently increased to 10k
D3). My 25-H is 71 ng/mL as of last week (lab 'normal' = 20 - 79 ng/mL). Here
are some questions I'd appreciate you considering addressing in Part 3.

* Do you think that some patients (like Shannon) have adverse reactions (and others don't) mostly due to random individual sensitivity or does it seem like there are may be some factors that could serve as indicators? For example, I don't even know if a person's size (kg) 'matters' either in the test result or in absorption.

* I've seen claims that some reasonable UV exposure can A) increase uptake of supplemented D3, or B) Is recommended (if possible) because 'UV-sourced D3' is somehow 'different/better'. Yet I haven't found any published discussion of A or B. I realize the answer is likely both complicated and uncertain, but would love to know if either A or B has been evidenced, is unevidenced but 'seems plausible' or unevidenced and doesn't seem plausible.

To be clear, I'm not asking for personalized advice. Just giving you N=1
context on one reader's questions: I currently have no apparent ill-effects
from supplementation. Based in part on your post, I'm now considering dropping
back to 5k IU D3 as my goal is really to ensure I'm not D3 deficient (not
mega-dose). I started supplementing initially due to diagnosed SAD and more
recently went up from 6k to 10k in light of possible CV19 bonus benefit (I'm
not at elevated CV risk anyway).

------
LatteLazy
Isn't medical error the number 3 cause of death in the US?

~~~
tedunangst
No.

------
SeanBean62
I liked the comment on the page - I will never give up my D

------
whoisjuan
I take 10000 IU but not daily. More like once every other day or basically
when I remember (more like the latter, 3 times a week). I don't like being
religious about it, so it makes sense to me to get a high dosis when I
remember.

Of course I don't recommend doing this way to anyone. Do a serum level test
and work from there.

~~~
core-questions
From the other comments here it sounds like that's pretty high. If you're
worried enough about it to take that much, maybe you should get yourself a
blood test done to find out what your levels are like?

~~~
whoisjuan
I already took a test and my levels were very low. That's when I started
supplementing. Taking another test soon to check levels again.

~~~
core-questions
Sounds like you have a good sane approach. Hope you do well.

