
SARS-CoV-2 positivity rates associated with circulating Vitamin D levels - spuz
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239252
======
macawfish
There is a whole body of research around the ways that vitamin D modulates
inflammation, helps regulate calcium homeostasis and strengthens circadian
rhythm. Here is some relevant research:

\- vitamin D is directly involved in regulating the renin-angiotensin system,
including ACE2 expression. (
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999581/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999581/)
)

\- vitamin D has been shown to have anti-inflammatory activity with respect to
cytokines specifically involved in advanced COVID-19 cases (
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164284/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6164284/)
)

\- vitamin D and magnesium insufficiency both cause hypocalcemia, which has
been connected to COVID-19 severity: (
[https://www.researchsquare.com/article/rs-17575/v1](https://www.researchsquare.com/article/rs-17575/v1)
)

\- magnesium and vitamin K2 also modulate calcium homeostasis ( you can look
this one up yourself I need to get off this phone )

^^^ this is a snippet from a letter I sent to the local health department. I
sure hope someone read it!

~~~
shadowmore
I keep seeing data points like this, but does supplementing vitamin D work?
Does it make sense to read things like this and conclude that taking a vitamin
D supplement pill daily is a good idea?

~~~
rossdavidh
There is a long history of taking pills of vitamins and minerals not being as
good as getting it the way we evolved for. We evolved to produce vitamin D by
getting sunlight. We are NOT evolved from nocturnal animals. A vitamin D
supplement might help, but a better idea is to take a walk in the park every
day, while the sun is up.

~~~
bird_monster
Sure, and that's great, but what about the scenarios in which I cannot walk to
the park (during 600+ AQI wildfires, as an example), is the reason I'd like
the data on supplementation.

~~~
undersuit
You can buy or make a SAD/Sun Lamp.

~~~
bird_monster
Sure, and that's great, but I'm asking about the efficacy of a supplement

~~~
DanBC
You're never going to get sensible dietary advice on HN.

Get sun. If you can't get sun you should eat a variety of food that contains
vitamin D. If you can't do that, you should take a supplement. Take the
supplement at the same time as you eat a meal, preferably a meal that has some
fat.

Here's the advice for England:

[https://www.nhs.uk/live-well/healthy-body/how-to-get-
vitamin...](https://www.nhs.uk/live-well/healthy-body/how-to-get-vitamin-d-
from-sunlight/)

[https://www.nhs.uk/conditions/vitamins-and-
minerals/vitamin-...](https://www.nhs.uk/conditions/vitamins-and-
minerals/vitamin-d/)

~~~
gerdesj
Freely available advice from the UK's NHS would seem to be a good idea. We
fund the NHS mostly out of taxation, so advice provided there has to be as
close to non partisan as is reasonably possible.

I personally don't give a shit if you are a foreigner. If the NHS website can
provide good advice and help someone - anyone, then my tax squids are being
put to good use.

There are bound to be other good sources of health related advice around the
place but why not start with the NHS and work out from there?

~~~
gridlockd
If you pay close attention, health authorities always play it safe, for
example by saying "there's not enough evidence". That's why they didn't
recommend masks in the beginning.

Then, if some sort of expert consensus comes up, the authorities adopt that.
When that consensus is challenged by new evidence, authorities are slow to
change, because that would be implicit admission that they were _giving the
wrong advice_ , which is not something that the human egos involved there can
easily stomach.

A good example for this is the food pyramid[1]. It was never supported by good
evidence, it was adopted through expert consensus (one might also call it
lobbying), and it was later removed from the guidelines. You can still see
posters of it hanging in doctor's offices, of course.

[1]
[https://en.wikipedia.org/wiki/History_of_USDA_nutrition_guid...](https://en.wikipedia.org/wiki/History_of_USDA_nutrition_guides)

~~~
rossdavidh
True that, but the incentives for government bureaucrats in the U.S. and the
U.K. are somewhat different. Of the two, the former seem more likely to be
swayed by industrial concerns/lobbying. Not saying that the U.K. is totally
immune to this kind of thing, but I'd trust the NHS over the USDA.

~~~
gridlockd
> I'd trust the NHS over the USDA

Yet, the UK essentially adopted the advice given by the USDA. Why? Expert
consensus is formed by research, which is usually funded by interest groups,
and a lot of it ultimately comes out of the pockets of US industry.

For instance, the lipid hypothesis (that cholesterol causes heart disease) has
been popularized once (with US industry support), became expert consensus,
despite lack of evidence to support it, despite lots of contradictory data.

Once something is expert consensus for a while, it becomes harder and harder
to challenge. At that point, there is no need for industry to control the
narrative anymore, the experts (who do not want to admit being wrong) will
control it all by themselves.

The point I am making is that the authorities are _the last ones_ to set
things right, their advice is forever outdated and therefore likely wrong.

------
ralala
Could it be that just both, vitamin D deficiency and covid-19 risk, are much
higher for people that stay inside most of the day (e.g. have office jobs)?
Vitamin D is created from sunlight. Covid-19 is transmitted by aerosols. Is
there additional evidence that Vitamin D supplements may help or do we just
know about the correlation?

~~~
spurgu
I know very little about nutrition but have wondered whether taking
supplements actually help, or if it's the process that _creates_ those
vitamins that's actually important/healthy.

Like in your example, being exposed to sunlight starts a process in our body
that's healthy for our bodies, and vitamin D is just a by-product... and
taking it as supplements wouldn't really do anything as we're missing the
process.

As I said I have no idea what I'm talking about.

~~~
heavyset_go
> _if it 's the process that _creates_ those vitamins that's actually
> important/healthy._

By definition, vitamins are substances needed by an organism that it can't
create itself, and must be obtained in its diet.

~~~
jwilk
Vitamin D is technically not a vitamin:

[https://academic.oup.com/ajcn/article/88/2/491S/4649916#1112...](https://academic.oup.com/ajcn/article/88/2/491S/4649916#111229508)

------
sradman
The prevalence of SARS-CoV-2 infection was 12.5%, 8.1%, and 5.9% for patients
with deficient, adequate, and high levels of serum Vitamin D, respectively.
This study clearly demonstrates correlation but further studies are needed to
establish causative links.

The data comes from Quest labs that allowed the researchers to use the unique
patient ID to associate SARS-CoV-2 PCR lab results with 25(OH)D blood test
results. The dataset includes 190K patients.

~~~
fiatjaf
No study can ever establish causative links.

~~~
samatman
"The effects of high-dose cyanide on mortality in lab mice" will establish a
very strong _correlation_ , with an impressive _effect size_.

I suppose inferring causality still requires a leap of faith...

~~~
Gibbon1
More recently I've seen more discussion of observational power. That's related
to bayesian probability.

If someone said they fed a 3 month old mouse a 0.1 mg dose of Chemical X and
it died immediately. Hard to argue that sample size of 1 means the result is
worthless anecdote. The observability is pretty good.

------
xiphias2
Data availability got much better in the past following years (as a software
engineer I can finally do modelling based on data published by medical
researchers), but it's still too slow, which costs real lives.

,,Data underlying the study cannot be made publicly available due to ethical
concerns about patient confidentiality''

I don't believe that any part of the data couldn't be made available
(D-vitamin level - age - covid test results at least, even if location/time
would be too sensitive to share). Not sharing any data has ethical concerns as
well.

~~~
violetgarden
I agree! It seems like it could have been anonymized. The government site I
check regarding covid news that is local to me has the person’s age, sex, test
results, and county. I don’t see how vitamin d levels could be an identifier.

Just venting - data during this pandemic has been one of the most frustrating
parts for me. Data should be one of the tools we can use to get through this,
but it’s been a struggle knowing what’s accurate and lack of certain
information makes it hard to make good decisions.

~~~
xiphias2
One interesting thing is that the Russian vaccine tests were criticized for
not sharing raw data by lots of researchers from western countries as well.

I'm definately taking vitamin D and not signing up for the Russian vaccine,
but it seemed hypocrytical to me that only Russian researchers were shamed for
not being transparent.

~~~
hcknwscommenter
"One interesting thing is that the Russian vaccine tests were criticized for
not sharing raw data"

I'm sure that, if one searched hard enough, one could find such a criticism.
However, most of the criticism centered around the fact that the vaccine was
"approved" on the basis of nearly zero actual human data.

~~~
xiphias2
I saw only 1 open letter signed by lots of researchers which contained many
problems with the experiment: the main one for me was that the results that
were supposed to be from independent experiments were extremely highly
correlated. The reason behind that correlation can be not enough original data
(cheating) or bad processing, but the western researchers asked for the
original data to find it out.

------
ineedasername
We don't know the source of the vitamin D: For example it's entirely possible
that the type of person who has higher vitamin D levels is the type of person
who takes care of themselves through things like vitamin supplements, and
people who take care of themselves are less likely to have preventable
underlying conditions.

So, as always, it's important to remember that this study was retrospective,
not experimental in nature.

~~~
rflrob
Or even that people who take supplements are more likely to get a “just in
case” Covid test than someone who doesn’t supplement.

~~~
graeme
This would mean we should expect positivity and vitamin d levels to correlate.
The study found reverse correlation.

~~~
MiroF
I can see how it's confusing, but no.

If the type of person to take Vitamin D comes in for a test with less symptoms
"just in case", then the probability that they are positive given that they
are tested is lower.

~~~
graeme
Oh you’re right. I didn’t think carefully enough. Thanks! This does seem like
a major factor to tease out.

------
sebst
There was recently a case in Amsterdam where visitors of a large night club
didn’t get infected before 11pm. After 11 the club had to close its windows
and people got infected.

Whenever there is a study about VitD deficiency, it could simply mean that it
has something to do with time spent outside and temperatures. Isn’t COVID less
likely to transmit outside?

~~~
BjoernKW
Yes, but that's due to aerosols being much more volatile outside than inside.

~~~
SpicyLemonZest
Certainly, but I think that still leaves a lot of room for a non-causal
correlation. In a toy model where Covid-19 is uniformly present in N% of
indoor spaces and 0% of outdoor spaces, we'd expect infection rates to
correlate strongly with vitamin D levels even if vitamin D doesn't affect the
virus at all.

------
sandstrom
I'm not arguing against this paper, or that Vitamin D could be very helpful
for covid-19 and other things.

But for casual readers it's good to know that Vitamin D is quite potent (it's
a steroid hormone, in the same category as estrogen, testosterone and
cortisol).

Too much is also harmful.

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

[https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-
st...](https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-story)

[https://www.devaboone.com/post/vitamin-d-part-3-the-
evidence](https://www.devaboone.com/post/vitamin-d-part-3-the-evidence)

------
jimmyswimmy
I'd be interested to see the results broken out by racial group. There is
evidence that blacks do not metabolize vitamin D the same way that whites do,
and the standard test for vitamin D concentration does not measure its
bioavailability accurately. This could strongly affect the results depending
on the racial distribution of participants. In other words this effect could
reduce the significance of the results.

Here's a popular article on the topic. [https://www.npr.org/sections/health-
shots/2013/11/20/2463933...](https://www.npr.org/sections/health-
shots/2013/11/20/246393329/how-a-vitamin-d-test-misdiagnosed-african-
americans) though there's plenty of research articles available.

The difference is that the test evaluated 25(OH)D concentration, and not
1,25(OH)D which is the useful (metabolized) compound. There is currently no
standard test for the latter, which is why they didn't do it. Though I would
prefer to see those results, it would be easier at the present time to
parameterize the study by racial group to reduce or eliminate this effect.

That said it would be nice if we could all just take a nice cheap vitamin for
this. Caveat: I am not in life sciences.

Edit. They do show a figure which breaks out the relationship by race.
[https://journals.plos.org/plosone/article/figure?id=10.1371/...](https://journals.plos.org/plosone/article/figure?id=10.1371/journal.pone.0239252.g002)
and it is much stronger for African Americans. Perhaps my hypothesis was
incorrect.

~~~
kenjackson
BTW, as someone who is Black — I didn’t find a single thing in your post
racist. It talked about race, but not in a way to oppress or demean any group.
At least that was my take.

~~~
crispyporkbites
It’s not a racist post obviously- but it is false to group people into the
American race definitions in a scientific discussion, because it doesn’t hold
true and has been debunked a long time ago as a genetic definition.

It can apply from a socio economic angle, but that applies only in America or
a country that uses American racial profiles for systemic racism.

Edit: Aware this is a controversial viewpoint in non-scientific communities,
so here's some interesting comments from Wikipedia on the subject:

> Modern scholarship regards race as a social construct, an identity which is
> assigned based on rules made by society.[2] While partially based on
> physical similarities within groups, race does not have an inherent physical
> or biological meaning.[1][3][4]

> Social conceptions and groupings of races have varied over time, often
> involving folk taxonomies that define essential types of individuals based
> on perceived traits.[5] Today, scientists consider such biological
> essentialism obsolete,[6] and generally discourage racial explanations for
> collective differentiation in both physical and behavioral
> traits.[7][8][9][10][11]

> Even though there is a broad scientific agreement that essentialist and
> typological conceptualizations of race are
> untenable,[12][13][14][15][16][17] scientists around the world continue to
> conceptualize race in widely differing ways.[18] While some researchers
> continue to use the concept of race to make distinctions among fuzzy sets of
> traits or observable differences in behavior, others in the scientific
> community suggest that the idea of race is inherently naive[7] or
> simplistic.[19] Still others argue that, among humans, race has no taxonomic
> significance because all living humans belong to the same subspecies, Homo
> sapiens sapiens.[20][21]

~~~
umanwizard
I’ve gotten blood tests done where the normal range for various parameters was
listed as being different for different racial groups.

If there is no correlation between genes and “American race definitions”, how
is this possible?

~~~
crispyporkbites
[https://www.nationalgeographic.com/magazine/2018/04/race-
gen...](https://www.nationalgeographic.com/magazine/2018/04/race-genetics-
science-africa/)

[https://www.eurekalert.org/pub_releases/1998-10/WUiS-
GSRD-07...](https://www.eurekalert.org/pub_releases/1998-10/WUiS-
GSRD-071098.php)

[https://theconversation.com/racism-is-real-race-is-not-a-
phi...](https://theconversation.com/racism-is-real-race-is-not-a-philosophers-
perspective-82504)

To add a bit more weight it’s worth reading the intro to race on Wikipedia
[https://en.m.wikipedia.org/wiki/Race_(human_categorization)](https://en.m.wikipedia.org/wiki/Race_\(human_categorization\))

~~~
umanwizard
I’m aware that race is not a strictly defined category, and that racial
classification is arbitrary to a large extent. However, this doesn’t answer my
question.

~~~
crispyporkbites
It demonstrates the logical fallacy - if it's an arbitrary classification, as
you say, how can those blood test groupings be accurate? They can, at best, be
arbitrary

~~~
umanwizard
“Arbitrary” doesn’t mean “uniformly random”. Even though the lines are
blurred, there is still a strong _correlation_ between being considered part
of a particular racial classification in the US and having certain genes.

------
Protostome
I work as a data scientist in one of the largest US healthcare companies.

We ran a similar analysis back in June and found comparable results based on
our claims data. People with low vitamin D rates had higher likelihood of
hospitalisation and mortality. Back there were less indications that vitamin D
has any effect on Covid severity, and when I presented the analysis to our
chief scientist he dismissed my conclusion.

~~~
spuz
Ok... but why was your conclusion dismissed? This is very troubling.

~~~
Protostome
Quoting him: "Our data is so noisy, you can't really infer such a relationship
from claims data" Since all those analyses are retrospective, it's not easy to
build a case that will show a causal relationship between the outcome
(hospitalization/death) and the covatiates (vitamin D levels). Some will say
that this is impossible and only prospective studies will provide an
unequivocal evidence.

Therefore, it is not rare that retrospective studies are encountered with
skepticism. What baffled me is that recommending people to take vitamin D has
almost zero negative consequences, so why not? the data supports it, even if
it's not a solid rock proof.

~~~
spuz
That makes sense to me. If the evidence is not rock solid, you probably should
not be making medical suggestions to your customers. The idea of my insurance
company suggesting I should take supplements where that isn't within the
typical medical consensus or part of government advice would make me
uncomfortable.

------
AlbertoGP
Dr. John Campbell, a registered nurse in the UK, has spoken about this subject
for months evaluating the evidence. You can find several videos about it in
his YouTube channel:
[https://www.youtube.com/channel/UCF9IOB2TExg3QIBupFtBDxg](https://www.youtube.com/channel/UCF9IOB2TExg3QIBupFtBDxg)

This would be the one to start with: “Vitamin D, large scale studies” (12
sept. 2020)
[https://www.youtube.com/watch?v=iNji13yoW9g](https://www.youtube.com/watch?v=iNji13yoW9g)

------
schwax
Derek Lowe wrote a post this week on the "bradykinin hypothesis," and how it
has been gaining traction as a unifying model that can explain many of the
observed effects of infection, including sensitivity to vitamin D levels.

[1]
[https://blogs.sciencemag.org/pipeline/archives/2020/09/08/br...](https://blogs.sciencemag.org/pipeline/archives/2020/09/08/bradykinin-
and-the-coronavirus)

------
guscost
Yes, this means you should measure your blood Vitamin D and supplement
whenever it shows up as deficient (much more likely in the winter). Yes,
correlation does not prove causation, and yes, the recent randomized
controlled study[0] may have problems too, but in aggregate the evidence is
overwhelming. Don’t forget!

[0]
[https://www.sciencedirect.com/science/article/pii/S096007602...](https://www.sciencedirect.com/science/article/pii/S0960076020302764)

------
meddlepal
Never purchased vitamin D before, if I were to walk into a CVS or Wallgreens
what would I be looking for? Is this something you can just buy OTC?

~~~
beagle3
It’s otc. You want D3 variant, rather than D2. There is some disagreement
about dosage - FDA RDA is 400IU daily for adults, but there are reasons to
believe it is way too low.

Personally, I’ve taken 10,000IU daily for years with only positive effects
(also Some K2 and Mg - they likely work in tandem). Deva Boone’s blog
describes a case where 5000 IU /daily over years was too much for one of her
patients. Do your own research.

There also reason to believe it should be take early in the day (say before
10am), as vitamin D is a derivative of sunlight (among others) and taking it
in the evening/night seems to mess the body’s internal clock. (Google “gwern
vitamin D” for more)

~~~
jsjohnst
I am severely Vitamin D deficient due to a medical condition I have which
prevents my body from absorbing VitD via the gut (which is how many consume it
the most, via food you eat, not via sunshine). I’m on prescription strength
VitD supplements and take weekly doses that are 50,000IU. I would not
recommend self medicating with high doses of Vitamin D without consulting with
a doctor because if you aren’t deficient like me, taking high doses like that
can be dangerous as the side effects aren’t fun.

~~~
alyandon
I have an actual minor deficiency as well and had accidentally bought the
wrong potency (the bottles are identical except for the 4 pt flyspeck font
specifying the amount) from the store and had been mistakenly taking
5000IU/daily instead of 1000IU/daily for about 6 months. When I informed my
doctor of my mistake, he ordered a test and although my serum vitamin D levels
were not outrageously high they were at the upper limit.

So definitely easy to "overdose" on vitamin D and as you point out - the
potential side effects are not pleasant.

------
mg
I often wonder how fast the effect of vitamins is.

Let's imagine would could measure the level of Covid-19 symptoms with infinite
precision. And let's imagine Vitamin D has a positive effect. And let's
imagine we have infinitely large test groups.

Then how long after the intake of Vitamin D would we see a difference in
symptom levels compared to the placebo group?

Would it take weeks? Days? Hours? Minutes? Seconds?

~~~
scottlocklin
Hours:

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

FWIIW vitamin-D level is almost certainly why brown people and nursing home
residents are disproportionately dying of Corona-chan.

~~~
bamboozled
What is corona-chan?

~~~
buzer
If it exists, there is probably a cute anthropomorphic representation of it.
[https://www.youtube.com/watch?v=iBoojBTEPaI](https://www.youtube.com/watch?v=iBoojBTEPaI)

------
esaym
So I eat two bowls of cereal with milk a day, live in Texas and out in the sun
several times a week (mowing, gardening, etc). Do I need to worry about
vitamin D?

~~~
Laremere
Your primary care physician is who you should ask. Mine takes a blood test
with the yearly physical, which includes a vitamin D measurement. They can
tell if you're deficient and by how much.

------
lebuffon
As a official member of the "old fart" society I have a memory of something
from 50ish years ago, probably in Time magazine, that documented the fact the
US military found cases of rickets associated with low vitamin D levels in
personnel stationed at the DEW (Distant Early Warning) line, a group of radar
stations in the high arctic. The cases were among people with darker skin. So
there's some old evidence correlating Vitamin D, skin shade and sunlight
exposure. Wish I could remember the source...

------
mattdeboard
I don't know anything about academic statistics. Is it a weakness in the
study's conclusions that the sample size from predominantly Black & Latino
communities is an order of magnitude smaller compared to non-Black & non-
Latino communities?

edit: I'm not trying to imply malice or anything, but I have learned the last
couple years how ethnic minorities & women are often underrepresented (or not
represented at all) in medical studies, leading to poor health outcomes for
those communities.

~~~
cacois
I have some experience in that area. If I'm reading this correctly, they don't
know race, only ZIP code. They are extrapolating race from zip code. They also
seem to be deriving results for extrapolated black/hispanic populations based
on using the other populations as a control.

Its really just a question of whether their sample sizes are large enough to
justify a conclusion about the overall population. They are reporting a 95%
confidence interval. Real back-of-the-napkin math (read: don't take this to
the bank) would say that a sample size of 9,604 could get you a 95% confidence
interval with a 1% margin of error on a population of 100 million. So it seems
they are doing ok, but this is not to say there are not a bunch of other
possible issues or confounds to consider if someone dug into the study.

------
MayeulC
Hmm, could this relationship also somewhat explain the bigger incidence of
respiratory viruses during winter, when sun shines less, and we produce less
vitamin D?

~~~
MichaelZuo
This is a possibility. Or at least it is a plausible mechanism of action for
higher susceptibility. If true we should expect seasonal variance in
prevalence to decrease as you move towards the equator.

~~~
gridlockd
There is in fact data that shows this correlation, I may post a source later.

~~~
londons_explore
It still isn't a strong indicator of causation, since nearly all seasonal
climatic effects diminish towards the equator.

------
jshaqaw
Our family takes vitamin d supplements. I’m not sure what the ultimate
efficacy is but the low risk-high potential reward seems compelling. My kids
think the yummy gummy versions are a treat anyway. Just be aware that like
most things you can take too much vitamin d. By all means take some supplement
but don’t overdo it or the low risk part of the equation changes.

------
Zigurd
Be careful with overdosing, though. Some people need high doses because they
are very deficient. It is sold OTC in high doses. The amount of vitamin D in
your body accumulates if you take it daily at high doses. Don't go overboard.
Beyond a readily attainable threshold, more is not better.

------
elil17
Do any medical experts know, does this mean I should take a vitamin D pill?

~~~
radu_floricica
IANAD, but reasonable algorithm looks like:

If you can test, test. Look online what normal levels should be - you'll find
several options, pick the higher ones (look for Vitamin D Council for an upper
bound recommendation)

If you can't test or you test below optimum and you can sunbathe - do that. A
lot. It's inherently safe as far as overdose goes. For skin cancer, it's
usually worth the risk, and definitely worth it during the pandemic (unless
you have specific reasons to think you're higher risk).

If you can't test and can't sunbathe... in normal times I'd suggest to
supplement except in summer. But in Covid times, I'd go with light
supplementation during summer (<1000 UI daily) and higher dosage staring
autumn (~2000 UI).

~~~
graeme
Note that not that much sun exposure is required. The dminder app is a good
way to estimate update based on sunniness and percent skin exposed.

~~~
Larrikin
The replies from the developer to reviews makes me not want to support this
dev. Any other good options?

------
sigmaprimus
Why is Vitamin D not called "Hormone D"?

I understood that vitamins could not be produced by the body, but hormones are
produced by our bodies. How many "Scientists" would argue that hormone D
therapy actually works instead of arguing against the efficacy of vitamin
supplements and lumping the oddball possibly miss named Vitamin D in with
them.

------
aschatten
Interesting study, but it’s has been suspected for long that vitamin D might
have all this effects.

Without being able to see the data, this does not feel right. I would like to
see how they did cross-validation, test/train split, assigned weights,
proportion of missing values. If you have data, this can be easily reproduced
and studied. What if it’s overfitting?

------
nimish
At this point it's worth questioning why viral diseases are so prevalent in
the winter in the Northern hemisphere and that they show a clear seasonality

Would make a lot of sense to test vitamin d deficiency (Inc beyond RDA) vs
immune system response

------
m12k
Most likely, what this shows is just that people with strong immune systems
that can fight off the corona-virus also tend to not have vitamin D deficiency
(in part because frail people tend to spend less time outside in the sun).

------
jacquesm
Question: Vitamin-D deficiency is also often associated with Vitiligo,
discoloration of the skin.

Is there any correlation between Vitiligo symptoms and COVID-19?

------
ColanR
It's nice that HN has finally moved beyond labeling Vitamin D's relevance to
Covid a conspiracy theory. I put some articles on here about it a month or two
(edit: 6 months) ago, and posters went as far as to go through my submission
history and call me a conspiracy theorist for my "history of posting debunked
vitamin D conspiracies".

Edit 2: how's this for ironic: looking back over the past year, the single
source of information about the virus that has turned out to 'get it right'
most frequently (not counting noise) is 4chan.

~~~
chimichangga
Fauci says that he takes vitamin D supplements and that they can lessen 'your
susceptibility to infection'

[https://www.insider.com/fauci-takes-recommends-vitamin-d-
and...](https://www.insider.com/fauci-takes-recommends-vitamin-d-and-c-
supplements-immunity-boost-2020-9)

~~~
ColanR
Glad he's finally willing to admit it. I hope the factcheckers stop calling it
fake news soon. I wonder how many people died because it wasn't taken more
seriously sooner.

~~~
electriclove
Sorry you are getting downvoted for having a dissenting view. Everything gets
twisted to become political. The same people shaming those for wearing masks
initially came around in their own way to advocate strongly for cloth masks.
The same people who refused to acknowledge Vitamin D benefits against Covid at
the beginning are coming around now. HCQ is even more political ("serious side
effects") in the US. It might be less political elsewhere.

------
phkahler
>> Until treatment and vaccine for coronavirus disease-2019 (COVID-19) becomes
widely available, other methods of reducing infection rates should be
explored.

Until we figure out how to profit, maybe we should let people use existing
stuff so they dont die?

Yeah, I woke up in a bad mood :-/

------
Keyframe
As with any source, reader be mindful of comments here on HN. When outbreak
happened and lockdowns were getting in place, you could've read here people
getting chloroquine and how to dose it yourself.

~~~
natalyarostova
The risk profile of vitamin d is different than chloroquine. Taking vitamin D
on weak evidence still passes cost vs benefit.

------
gridlockd
One more for the pile of evidence that Vitamin D supplementation may(!) help.

It baffles me that masks are officially recommended despite scant evidence
that they help, yet Vitamin D is ignored.

EDIT: This is a not an argument against mask usage, it's pointing out the
double standard applied to two different cheap and low-risk interventions.

~~~
Renaud
I'd like to offer a counterpoint on the masks: as soon as the epidemic
started, the Hong Kong population -remembering SARS 15 years ago- started
wearing masks and sanitizing hands.

Hong Kong is one of the most densely populated area in the world. There is no
way to implement effective social distancing here

The result so far? one of the lowest rate of infection and death per capita of
any developed country: 675/M and 12/M respectively.

To put this in perspective, the UK and US are at 50x that death rate.

So we may speculate about what had a strongest effect -sanitizing hands,
masks, temporary closure of schools and entertainment venues, partial work
form home- but it seems difficult to argue that masks have no effects as most
of these measures were also tried elsewhere. A major difference being that, in
HK, no-one leaves the house without wearing a mask.

~~~
gridlockd
I'm not arguing that masks don't work, I'm arguing that the evidence is of low
quality. Not that the evidence is wrong, or that people shouldn't wear masks.

If you're advocating the wearing of masks premised on that sort of evidence,
you should be advocating Vitamin D supplementation, and you probably should be
advocating Zinc+HCQ as a prophylactic, because you just lowered your
scientific standards by that much.

~~~
nicoburns
What sort of evidence would you like to see?

~~~
gridlockd
Well, of course I'd like to see a double-blind placebo-controlled gold-
standard trial on a million subjects from diverse backgrounds!

In fact, I don't need more evidence to wear masks. I have no problem with
wearing a mask. I have no problem with advocating the wearing of masks in an
_honest_ fashion. It's plausible that masks do help to some degree. It's
however also plausible that they hurt in some ways, that they serve as a
reservoir for viruses and bacteria.

If anything, I have a problem with the intellectual dishonesty surrounding the
advocacy of masks.

~~~
Renaud
If you see the various implementations of measures in different countries as
large scale experiments, I think you can derive some useful information and
answer your own questions.

There is maybe some point of diminishing returns in wearing masks, but what
the limit is isn't clear. Sweden seems to agree with you and against general
use of masks, although my trust in their approach is limited by their pretty
terrible results: death rate of nearly 600/M against HK's 12/M.

Regarding increased risk of falling ill because of the mask, there is not much
evidence to support that. That's not saying it doesn't or can't happen but
while you emphasise a lack of evidence to convince you that masks are
worthwhile at scale, there is even less evidence that wearing a mask will
cause any other type of hurt that would cancel-out the benefits.

I personaly hate masks, they itch, are uncomfortable and they pollute. It's
clear they are not a panacea. They are however part of the small set of
limited practical measures that we can take to help slow the rate of infection
(by limiting the exposure of others to the crap we exhale).

Hong Kong will be an interesting experiment to follow because I foresee that
people will continue wearing masks long after everyone else. We'll see the
long term effects this has on the 8M people living there. I'm sure it will be
worthy of a few papers.

~~~
gridlockd
> Sweden seems to agree with you and against general use of masks, although my
> trust in their approach is limited by their pretty terrible results: death
> rate of nearly 600/M against HK's 12/M.

No matter how often I say "I'm not against masks", people still read it is
"this guy is against masks", merely because I question the quality of the
scientific evidence. No sane discussion on this topic is possible anymore,
it's all "which side are you on, boy?", which is disheartening.

> That's not saying it doesn't or can't happen but while you emphasise a lack
> of evidence to convince you that masks are worthwhile at scale, there is
> even less evidence that wearing a mask will cause any other type of hurt
> that would cancel-out the benefits.

I literally said I don't need more evidence in favor of masks. It's not about
masks, it's about Vitamin D _in light of our treatment of masks_. I don't need
more evidence in favor of Vitamin-D supplementation, either. Go for it, just
be honest about it.

~~~
nicoburns
> No matter how often I say "I'm not against masks", people still read it is
> "this guy is against masks", merely because I question the quality of the
> scientific evidence. No sane discussion on this topic is possible anymore,
> it's all "which side are you on, boy?", which is disheartening.

You've said you're against advocating mask usage. We are arguing that although
there could certainly be more and better evidence, that there is more than
sufficient evidence to advocate for their widespread usage.

~~~
gridlockd
> You've said you're against advocating mask usage

I haven't said that either.

