126 comments

[ 10.6 ms ] story [ 2998 ms ] thread
Not by me. I'm D-deficient, had gastric sleeve surgery, surprisingly it's the only deficiency I have regularly. I often forget my D... but been taking it religiously and asked my doctor if it's okay to add an extra 5000 iu per week, and he said it was fine and a good idea because of how low I normally run.

I've got a new formulation coming soon though that has vitamin k mixed in w/ 5000 ius, and a separate calcium/magnesium pill to make sure my bones stay strong. Will get re-tested next month and see if I beat the deficiency. I'm sure there's plenty of things but seemed like taking D probably is biggest (other than distancing) due to my already extremely low normal levels.

Worth considering if you're eating too little fat, you may have problems with absorption of fat soluble vitamins like D and K.
This is a great callout and a good warning for folks. I've had mild Vitamin D deficiency which was diagnosed by a doctor many years ago. I was given Vitamin D supplements, which I stocked up on more than usual recently due to my staying in all day due to WFH and not getting any sunlight.

I used to take 50mcg of D3 1-2x a week and I upped that (without consulting a doctor) to 5x a week. Within two weeks, I started having extreme thirst. It was crazy to the point where I drank so much water that I could hear it sloshing in my stomach yet my mouth was parched dry and I was still very thirsty.

I did a quick Google search and found that this was actually a thing [0]. I stopped my Vitamin D supplements the next day and my thirst went away that same day. Be careful folks.

[0] https://www.express.co.uk/life-style/health/1203879/vitamin-...

I read somewhere that prolonged high doses of vitamin D might have adverse effects on bone strength making them more brittle, but I'm unsure about the source. I personally have celiac disease and hypothyroidism am also having issues keeping the D up (heh heh). I take about 200ug daily with vitamin K and I'm thinking about increasing it temporarily to double of that. Generally it shouldn't be an issue with short term higher doses, but nearing a 1000ug daily dose for prolonged periods (months) can be dangerous.
That is only true if you also have a potassium deficiency and low K2-MK7. That's why, when testing D levels, it's also important to test Ca levels. And even then, you have to be taking very high levels of D. More on the order of 50K UI a day for a long time.
(Med student here with only limited knowledge).

This is correct. The active form of Vitamin D (Calcitriol) can be both helpful and harmful to bone health.

I think the mechanism is not fully understood but in short doses it stimulates bone growth and is a treatment for osteoporosis. In chronic doses it actives cells caused osteoclasts that reabsorb bone.

Do you know the breakpoint? What's a short dose, and when does it become chronic?
Cholecalciferol is used in over the counter supplements, not calcitriol (which is the active vitamin D form).

There also is a negative feedback for the conversion, that explain why there are so few acute vitamin D poisoning.

I believe that's why some nutritionists recommend supplementing with Magnesium when taking vitamin D.
Well considering 1 hour of spring, summer fall skin exposure at noon will generate between 10,000 and 20,000 IU of Vitamin D, I’d be interested in what would constitute a high dose.

These scientists believe the RDA of 600 IU was a statistical error, and that the correct amount should be 8,995.

https://pubmed.ncbi.nlm.nih.gov/28768407/

Considering how much vitamin D is generated during sun exposure, 600 IU seems ridiculously low.

Is it safe to take a high dose of vitamin D in supplement form? I ask only because the National Health Service (NHS) in the UK warns not to take more than 100 micrograms of vitamin D. 5000 iu (International units) is approximately 125 micrograms of vitamin D.

Here is what the NHS website says:

"What happens if I take too much vitamin D?

Taking too many vitamin D supplements over a long period of time can cause too much calcium to build up in the body (hypercalcaemia). This can weaken the bones and damage the kidneys and the heart.

If you choose to take vitamin D supplements, 10 micrograms a day will be enough for most people.

Do not take more than 100 micrograms of vitamin D a day as it could be harmful. This applies to adults, including pregnant and breastfeeding women and the elderly, and children aged 11 to 17 years."

https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-...

I am not a doctor but fwiw I was told by an NHS doctor that the most recent scientific understanding of vitamin D is that the recommended dose (based on old science) is far too low and 5000 per day is a good amount for someone in the UK (due to the amount of sunlight we get on average here).
Units, please. He said micrograms and it sounds like you’re talking about IU.
Remember hearing a podcast (the drive peter attia with someone else) and they were saying up to 10k iu there is no harm, anyway I heard somewhere else that vitamin D also overexpreses ACE2 so you probably just want to take between 1k and 2k covid 19 wise. Not a doc though
https://www.healthline.com/nutrition/how-much-vitamin-d-is-t...

"According to the Institute of Medicine, 4000 IU is the safe upper level of daily vitamin D intake. However, doses up to 10,000 IU have not been shown to cause toxicity in healthy individuals"

Probably God to avoid testing the limit if you can.

Are you sure you are a "healthy individual", if you've already diagnosed a health problem that vitamin D can treat?

Wow. 1 IU is the biological equivalent of 0.025 mcg cholecalciferol or ergocalciferol

Is there any nutrient that is essential in a smaller quantity than that?

My doctor believes it's safe, at least. I take 15000 IU on his advice (ramped up in 5000 IU increments until my bloodwork came back with acceptable levels).
I hope your K formulation also has K2, which seems like the more important and bioavailable one.
And if people hoard it and it's out of stock, you can just go outside!
It doesn't take hoarding, although that doesn't help. There are precious few products that can stay on the shelves when everyone decides they need some at once.

At northern latitudes, there isn't an available amount of sunlight, such that dark-skinned people can synthesize a healthy amount of vitamin D. Indeed, this is probably why light skin is selected for at those latitudes.

As a silver lining, I hope this crisis will provoke awareness of that fact. In most parts of the US, people with dark skin should definitely be taking supplemental Vitamin D. Really everyone should, unless they're a light-skinned sun-worshipper living in the Sun Belt.

Even if only white people are able to improve their outcomes, isn't that still a lot of people that would benefit? It seems like you're being a bit too negative here. It might be enough to slow the virus, which helps everyone.

And maybe the supplements are easy enough to make... They can probably be ramped up long before a vaccine comes along.

No. Avoiding a stroke spreads virus more than having a stroke and dying.
I'm confused. If vitamin D imoroves covid outcomes, and supplements run short, shouldn't we be happy that vitamin D is naturally accessible to many people?

It's harder to obtain naturally for blacks living in Seattle than whites living in Arizona. But it's still a good thing if it reduces covid deaths, right? And may slow the spread, therefor benefitting everyone?

Light skinned people shouldn’t get their vitamin d from the sun. The skin cancer risk far outweighs any benefit.

If it becomes scarce look up how to make vitamin d with mushrooms left in the sun.

You know white people aren't nocturnal vampires hiding behind parasols during the day, right?
Speak for yourself. My dermatologist won't let me out in the sun or the full moon (the latter because I might turn into a werewolf).
This is nonsense. 10-30 mins of sunlight a day without sunscreen for caucasians is something on the order of 10,000 IU of Vitamin D. You can do this safely without the worry of skin cancer.
Tell it to every derm I’ve talked to or read.
It might be good to exercise a bit of common sense before believing everything a doctor tells you.

How likely is it that getting even small amounts of sunlight is horribly dangerous? Do you believe in evolution? (For that matter, if you instead believe in creation by a benevolent god, you get the same answer.)

That's not even wrong when you haven't specified anglenpf sun (latitude or time of day.)
Clothed? Naked? In shorts?
It is hard to reconcile the fact that it's so easy to get enough D from sun in a short time with the fact that deficiency levels are roughly 40% in the US, with insufficiency (20-30ng/ml) much, much higher than 40% (and also high is much of the rest of the world). Look at the world chart in the paper (copied from Palacios et al review): 73% insufficiency in Austrelia, 61% in Britain even in summer, etc.).
This is an old wives’ tale. Most recent research indicates that moderate sun exposure without sunscreen (and without burning) is protective against many forms of cancer, including melanoma.

Furthermore, oral vitamin D supplementation is not proven to have the same benefits as endogenous D production, possibly indicating that the sun/skin interaction is doing something a little more complex than we currently understand.

I still supplement, of course. We’re all allowed a bit of magical thinking.

> Really everyone should, unless they're a light-skinned sun-worshipper living in the Sun Belt.

I hesitate to take any medical advice from the internet, but from what I can tell searching around a bit, the general consensus is that somewhere between 10 to 30 minutes of direct sunlight a day is more than sufficient (depending on how high the sun gets in the sky at your latitude and time of year..)

Hanging out on my porch for an hour a day seems to have me covered, despite living near Canada.

but what puzzles me about that direct sunlight recommendation: is it full-body (which is kinda impractical for most), shorts or trousers, how does it scale? Basically, 10-30 minutes just equates to what you should do anyway: go out and practice humanities special skills a little.
The guidance I've read seems to assume a t-shirt, maybe shorts. Bare face and neck. I'm not sure it's so critical though; I've been sunburnt through a tshirt before.
My doctor told me plenty of Americans have trouble making vitamin D even with sun exposure.
Why is that? Is there some missing ingredient?
People don't spend enough time outdoors to generate a sufficient amount of vitamin D.
The idea is that if vitamin D improves outcomes for covid 19, and the stores are all out of the supplements, then you can go in your backyard instead.
Backyards are relatively uncommon in some places in America: lots of high-rises, many without balconies.
That, and there isn't enough sunlight in many places, and many people's bodies can't make enough Vitamin D with sunlight (and the body's ability to do so decreases as you age).
That assumes that (a) there is enough sunlight available, and (b) your body is capable of making enough Vitamin D from sunlight.

(a) is not true in many places, and (b) is not true of many people (and it gets less true as you age).

From a public health standpoint, it's still good even if it only helps some fraction of people. I think that fraction is pretty large.
There are lots of other good health reasons to go outside, and I'm certainly not saying not to. I'm just saying you might not want to assume that just doing that is sufficient for your Vitamin D needs.
For what it's worth, I've been curating research on over-the-counter interventions for Covid-19 here: https://www.reddit.com/r/covid19stack

The research on vitamin D has been discussed extensively there over the last couple months.

This article (and the linked citations) misses a bunch of the most important theorized mechanisms of action, most notably that vitamin D plays a role in regulating blood clotting and having adequate levels may prevent the kind of sudden deaths from stoke we've been seeing in people who seemed to have gotten over the disease with otherwise mild symptoms.

Author of the review here. Happy to have addition suggestions for papers to include in the review. I looked at the Reddit group you linked and saw only citations of Alipio et al and Grant et al (from several posts), both of which I already cite. The review says of the Grant et al paper that it "broadly reviews evidence for D to help with infectious diseases, pneumonia, and inflammatory cytokines that damage the lungs and discusses some of the aspects of COVID-19 infection that are known to relate to things known to be also relevant to vitamin D." So not quite sure what it is that you are suggesting be covered that is not.

The review is not meant to be a thorough description of the biology at the intersection of vitamin D & COVID-19. The point of bring up the refs I have in section 8 is to point out that there are good causal mechanistic biological arguments for D's usefulness against C19, to help justify a call for additional data gathering.

Your reddit group looks fine and all, but it isn't the same as a single document that concisely collects all the best evidence for the potential of vitamin D in a well organized way.

Vitamin D is under studied because it cannot be patented (my doctor told me).
I've heard the same thing. No economic incentives compared to making a custom drug.
You've heard nonsense. There's tons of studies and clinical trials about the use of vitamin D. Here's an article listing just a few: https://www.medicalnewstoday.com/articles/322619

Every time you "hear" something about a topic that's important (e.g. in this case: health), just don't take anyone's word for it (doctors are people, too and have their cognitive biases and non-fact based opinions).

It's not that hard to look this stuff up and just do a quick check in relevant publications or sites like research.net - https://www.researchgate.net/search/publication?q=vitamin%20... - to get a more accurate picture.

> It's not that hard to look this stuff up

Aside from the fact that most health studies papers are retracted within 10 years, or found to be the opposite of what was claimed.

Which is less annoying than people like you who fetishize anything published. I suggest you learn what "peer review" actually means before telling people to run off and read about false health claims.

Why don't governments fund the research though?
(comment deleted)
They do: https://www.npr.org/sections/health-shots/2018/11/10/6665455...

https://www.lifeextension.com/featured-articles/2010/12/fede...

It's just that not everyone likes the results... If a doctor's cognitive bias leans towards "alternative medicine", for example, they don't want to accept certain findings, so they ignore them.

The real complaint those people have is "there's not enough (government-funded) studies about [remedy] that fit my preconceived convictions". At least that's my suspicion - I could be wrong of course.

Your doctor is talking nonsense. There's mountains of studies on things that can't be patented. We don't have studies on much of anything wrt COVID-19. And most of the energy has gone to hydroxychloroquine whose patent expired long ago.
but these studies are all relatively underfunded and underpowered relative to the stringent approval process for new prescription drugs, so I think the point stands.
Vitamin D doesn't require FDA approval. It's already rated as GRAS and is prescribed for known benefits.
This is almost certainly true, at least in part. Fasting is another such intervention.

The patent system is probably an overall benefit, but as with everything else, it can't be better in each and every case.

Sunlight as a treatment for COVID-19? Where did I hear about this before.
Perhaps irradiating yourself with UV rays might help after all!
There was some discussion about this on another thread: https://news.ycombinator.com/item?id=23079976

Essentially, one of the theories is that severely low Vitamin D can cause a hypercoagulable state and also increase the risk of the “cytokine storm” often observed in Covid-19 patients.

Not a very good review. We know that sunlight exposure is associated with lower all-cause mortality [1]. However, vitamin D supplementation has no effect on mortality [2].

Current thinking is that it is the nitric oxide rather than vitamin D that causes the benefit from sunlight [3].

So, if you want to have the best of both worlds, you should go out in the sun rather than using vitamin D supplements.

[1] https://www.ncbi.nlm.nih.gov/pubmed/24697969

[2] https://www.ncbi.nlm.nih.gov/pubmed/31405892

[3] https://www.karger.com/article/FullText/441266

Moreover, more outside time is associated with many other healthful activities. The correct model is that people who care about their health spend more time outside and therefore have higher vitamin D levels, not that higher vitamin D levels cause a dramatic effect on health. Taking vitamin D supplements if you are not deficient isn't going to make you care about your health more and is unlikely to have a significant effect on your mortality.
Don't people who take Vitamin D supplements _also_ care more about their health though?
(comment deleted)
Eh or just want to pretend to care about their health and the cost of being guilt free about it is a monthly vitamin D bottle.
In that case, the direction of causality is also reversed. Caring about health -> higher vitamin D, not the other way around, exemplifying my point. It's the caring about health that significantly reduces mortality, not the vitamin D, so implementing vitamin D supplementation as public policy to fight Covid-19 is unlikely to have an effect.
Fwiw, much of Western Europe is vitamin d deficient through no fault of their own. There's just too much cloud cover. Thankfully the past few weeks have been really nice.
Not enough existing research controls for when in the day vitamin D is taken or for other related nutrient levels (K, Mg).

Vitamin D is part of a whole complex network of signaling processes related to (at the very least) regulating circadian rhythms and how is calcium absorbed and used in the body.

I could see how taking vitamin D in the evening would actually be harmful if it disrupts melatonin synthesis. Do existing studies control for this? If they are, they're hard to find.

Until I see vitamin D studies controlling for those things, I take meta-analyses like that with a grain of salt. And I'll keep taking vitamin D in the mornings + magnesium in the evenings when I'm depressed in the winter. It sure seems to help.

Said as respectfully as I can, it seems like there's a lot of post-hoc justification from the supplement crowd.

I.e. 'Well, no effect was observed because Y wasn't done simultaneously.'

Which isn't to say vitamins aren't under-studied and -prioritized.

But is to say, it feels unscientific to always quibble over experiment design after the results show no effect.

> it feels unscientific to always quibble over experiment design after the results show no effect.

Respectfully, this is exactly what science is. The process of finding potential confounding variables and controlling for them in a new study is critical.

The OP isn’t saying the original study is wrong, or falsified, or whatever, just that it might not account for a particular effect. Someone should study that effect!

There is a lot of untestable post-hoc armchair experiment criticism from the supplement crowd, but this isn’t an example of that!

There are an infinite number of confounding variables in biological systems. Ergo, there are an infinite number of reasons to dismiss any particular study.

OP's suggestions are tightly scoped and proceed from a basis, but there is a point where you're dismissing concrete evidence on the basis of supposition.

I'm not usually motivated by these discussions, but it does seem like it's worth testing the difference between morning and evening for taking something that's related to circadian rhythms.
>I could see how taking vitamin D in the evening would actually be harmful if it disrupts melatonin synthesis.

How would this work? From my understanding, vitamin D blood concentration takes quite a while to build up due to the fat soluble nature, and taking a single pill doesn't cause an immediate spike just like staying inside for an entire day doesn't cause a drop.

Here's a study showing a marked circadian rhythm in serum 25-hydroxyl vitamin D levels. There are actually lots of theoretical papers about this kind of thing, yet somehow so many of these nutritional studies seem oblivious to them or something.

https://pubmed.ncbi.nlm.nih.gov/25788054/

If you dig a little you'll find a similar situation with Mg/Ca/vitamin K/vitamin D. There are lots non-controversial evidence and understanding of the relationships between them, but the nutritional studies on vitamin D supplementation seem all but oblivious to that information.

So that study seems to conclude that the blood concentration of vitamin D varies according to circadian rhythms.

That's an interesting finding, but what I'm saying is that I don't think taking a vitamin D pill has an immediate effect on your body's vitamin D levels. That's why it takes weeks or months of supplementation before you see it reflected in blood tests.

One issue here I'm realizing is in a difference of assumptions... I'm used to taking vitamin D3 drops under my tongue, which I imagine absorb differently than capsules.

But even so, fat soluble substances can get into the blood pretty quickly when you ingest them, well within the timespan of one day.

So I'm not sure if I understand your reasoning. Can you link to a source?

Something I'm reading now that sounds similar to what you're saying is that during supplementation, it takes a while for serum vitamin D levels to reach a steady state. Maybe that's what you're referring to?

Edit: check this out https://www.sciencedirect.com/topics/medicine-and-dentistry/...

> After an oral dose of vitamin D, blood levels begin to rise at 4 hours, peak by 12 hours, and return to close to baseline by 72 hours.

In this article, I take "baseline" to refer to what I called "steady state" earlier in this comment.

I've been wondering about melatonin.

It started when I heard about umbilical stem cell injections on the joe rogan episode with mel gibson. I started to look into it, and mesenchymal stem cells seem to really "fix things" that have broken down in your body. The more I read about them, the more I think they're going to be a powerful way of staying younger and fighting aging.

And then I read that melatonin is what regulates the natural generation of them in our body. Hmm.. probably something you shouldn't disrupt.

Is it the UV, or just the visible lights? i.e., can you get some of the benefit from LEDs at sunlight temperature?
UV-B makes your body produce Vitamin-D.

So, special LED that can emit UV helps for that, too, but carefully.

Oh and ordinary window glass completely blocks UV rays.

Every time I consider adding vitamin supplements to my diet, I'm confronted by the fact that the entire supplement industry is unregulated in the United States. How do you know the supplement you're taking is pure and of the listed dosage? You don't.
I'm pretty sure the "regulators" don't examine every molecule of atmosphere going in your lungs, nor every wild blueberry that gets eaten. If I walk out my house to the nearest farm and buy some chickens, I somehow don't need a "regulator" to bless the occasion. And yet, well-"regulated" iatrogenic deaths cause non-negligable mortality in USA [1]. You can compare the rates of poisoning yourself (dietary supplements vs regulated prescription drugs) as reported by the American Association of Poison Control Centers [2]. The rates of death due to contamination, or for other reasons, are not comparable.

This is meant to suggest you may wish to revise your risk analysis.

[1] https://jamanetwork.com/journals/jamanetworkopen/fullarticle...

[2] https://www.aapcc.org/annual-reports/ , in particular see page 1239 of the 2018 full report https://piper.filecamp.com/uniq/meDKF2EpE2jsmTOs.pdf

If I buy chicken meat and the package has pork in it, I'm going to notice. But if a vitamin supplement is actually nothing but chalk, would I notice? Probably not. Nor would it poison me, but I think getting ripped off is more likely than being poisoned.
There are a couple of well-regarded private organizations in the U.S. which write standards for and verify supplement manufacturers, one of which is United States Pharmacopeia (USP). See https://en.wikipedia.org/wiki/United_States_Pharmacopeia They serve a similar function as UL does for electrical and fire safety; and like UL some their standards are incorporated into the regulations of the U.S. and other countries.

Only a handful of well-known supplement makers are USP verified, AFAICT. (Note, verified is different than simply claiming to adhere to USP standards. It's like the difference between FIPS compliant and FIPS certified.) I try to buy Nature Made, a common brand in pharmacies which will usually carry the USP Verified mark, though it's product specific (see http://www.naturemade.com/usp).

Like with UL, this doesn't mean you're not buying useless crap, but it means you're unlikely to buy crap that will kill you, which is adulterated, or which isn't manufactured to minimum standards of safety (e.g. lead content--many supplements contain surprising levels of lead[1]).

[1] Not surprising if you consider how ubiquitous lead is in industrial environments, and that using non-contaminated materials in your food processing chain requires comprehensive, sustained efforts which translate to $$, especially in an age when so much industrial equipment comes from overseas.

EDIT: Consumer Reports details four private verification programs for supplement makers, including a table of testing regimes: https://www.consumerreports.org/supplements/how-to-choose-su... To me USP looks the best--store bought samples, more regular testing, stricter criteria for ingredients. The other 3 players they discuss are NSF International, UL (branching out, I guess), and ConsumerLab.com.

Yeah, I was going to post something similar. Lots of evidence for vitamin D deficiency causing all sorts of issues. Very thin evidence that supplementation helps. Better evidence that producing vitamin D naturally via sunlight helps. Which suggests that the D may well be a mostly irrelevant byproduct of the pathway that matters.
Author of originally linked post here. I welcome your constructive suggestions to make the review better. I intend it to be the best review on the internet of the best-available data on vitamin D & COVID-19 and think that it probably is currently.

The best method of increasing D levels to avoid deficiency is not the main point of the article. I have added a paragraph to note the debate on whether sun is better than supplements, but covering that debate adequately is beyond the intended scope. The urgent point is to get more data on D levels by patient vs. case severity/outcome. Such records should already exist in sufficient quantity if we can just get the right people from the right orgs (Kaiser? VA? big hospitals?) to simply aggregate the records and analyze or partner with researchers who will.

Dr. John Campbell, an educator in Northern England who's been doing daily Youtube updates on Covid news since January I believe, has put out a few videos from time to time related to vitamin D:

https://www.youtube.com/watch?v=W5yVGmfivAk - A month ago https://www.youtube.com/watch?v=GCSXNGc7pfs - 3 weeks ago https://www.youtube.com/watch?v=K-mHCn74E5o - 3 days ago

He suggests vitamin D deficiency may play a partial role in explaining higher mortality rates among people with darker skin (other important social disparities notwithstanding).

I believe he has claimed that vitamin D deficiency is associated with worse upper respiratory tract infections in one of the earlier videos.
He did. And he recently did a video talking about british research, which, having adjusted for socio-economic factors showed that the darker the skin colour the more likely the person would be to develop complications. His point here was that, dark skin impedes vitamin d generation.
It should be noted that while he does have some qualifications due to being a nurse and a nursing teacher, he's a Doctor in Philosophy and not in any medical/science field. It doesn't dismiss his claims per se but I still think he's using his Doctor title in a somewhat misleading way in this Covid19 context where a lot of people seem to think he's actually a medical doctor which he's not (edit: and this can be easily verified by just skimming through most comments on his videos which praises him in that regard).
This is kinda true, though he has earned the right to call himself a doctor, and I dunno if he should have to constantly have to add "though not in medicine!" Maybe he should? I don't know if "misleading" is the right word. He does seem to have expertise in the nursing field he's teaching FWIW, but yeah I researched him several months ago and found his linked in page which said the doctorate is in philosophy.
I've watched more than a dozen of his videos and assumed he was an MD. So I guess I feel mislead.
A doctor should not refer to themselves as a doctor when a doctor of a different field.

That's just wrong and abuse of authority. If he did that on philosophy he'd be ripped a new one

"Dr." for 'doctor' is the continental titulatur for finishing and successfully defending your doctoral thesis, thus attaining your doctorate. PhD is one of the US-variants of a doctorate. Reading 'doctor' and thinking 'MD' for 'Doctor of Medicine' is a mistake, although understandable when talking about medical issues. From Wikipedia I understand that f.e. in Canada MD is an undergraduate titel.
His PhD is in medical education, so I don't think it's fair to say it's not in a medical or science field. His online bios are clear enough about this, so I can't see how he's misleading anyone.
Very important to remember that Dr John Campbell isn't a medical doctor. He's a nurse with a PhD in learning.

I'm still waiting for the statistics where skin colour is correlated to income levels. Then I suspect we'll see the real issue. Poorer people living more densely.

Ben Goldacre (and others) have done a rapid assessment of covid-19 risk. https://opensafely.org/outputs/2020/05/covid-risk-factors/

> Results: There were 5683 deaths attributed to COVID-19. In summary after full adjustment, death from COVID-19 was strongly associated with: being male (hazard ratio 1.99, 95%CI 1.88-2.10); older age and deprivation (both with a strong gradient); uncontrolled diabetes (HR 2.36 95% CI 2.18-2.56); severe asthma (HR 1.25 CI 1.08-1.44); and various other prior medical conditions. Compared to people with ethnicity recorded as white, black people were at higher risk of death, with only partial attenuation in hazard ratios from the fully adjusted model (age-sex adjusted HR 2.17 95% CI 1.84-2.57; fully adjusted HR 1.71 95% CI 1.44-2.02); with similar findings for Asian people (age-sex adjusted HR 1.95 95% CI 1.73-2.18; fully adjusted HR 1.62 95% CI 1.43-1.82).

He talks about it here: https://twitter.com/bengoldacre/status/1258372975004389379?s...

Can someone tell me why HN is so obsessed with Vitamin D? I see a Vitamin D related article on the front page every few months. Also, https://hn.algolia.com/?q=vitamin+d shows a lot of articles about Vitamin D with a lot of upvotes.

Note: I supplement with Vitamin D daily, so no hate at all, just curious.

People who spend a lot of time indoors are generally deficient.
Programmers tend to not go outside as much, in the batcaves creating value many times in the dark of night.
Bring up a picture of the sun on your monitor?
A low-cost Vitamin D blood test was FDA approved in 2011, and since then Vitamin D deficiency diagnoses have skyrocketed. Plus, the narrative works (humans need sun for vitamin D, but now humans are inside, thus humans need to supplement D).
My guess would be, its a low toxic, proven beneficial substance that health hackers can play with.

Less controversial politically than drugs.

Additionally those in North Europe and Canada often cannot get it naturally for about a third of the year.

Not sure but I’ll submit a hypothesis that many people here sit inside mainly dark spaces all day and don’t always feel great. And because that doesn’t seem avoidable, hacking the system is a natural action of many here.

We all know we should probably get outside more for health.

It’s not just HN, people are always intrigued by the idea that they can improve themselves by taking supplements you can buy at the store.

I think it speaks to everyone’s desire to improve themselves, but also to our desire to improve ourselves without putting in too much effort. Taking a pill every day feels like a small, token accomplishment for your health without breaking a sweat.

There are also a lot of narratives floating around about deficiencies, or speculation about optimizing levels. This leads many people to assume that more is better, which in turn leads to excessive dosing. Hypervitaminosis D is a real condition that can happen with regular, over the counter supplements.

The truth is that yes, the average person in North America could use a little more Vitamin D. But it’s also true that most of us could get that Vitamin D from paying even minor attention to our diets and getting a little bit of sun in moderation.

There’s not much harm in taking small doses of Vitamin D, but beware of taking some of these excessive doses discussed online for extended periods of time without bloodwork.

Can't speak to the general point, but for COVID-19 in particular, it's starting to look like this matters. And not surprisingly, we're all kind of obsessing on that. If something so simple can keep people off ventilators, it's surely worth pursuing.

Past that, someone I know who lived in Alaska a few years started developing weird symptoms, including a declining ability to balance. Turned out she had low D, and once she fixed that, the symptoms all went away.

Comparing the segment of the general population with the lowest vitamin D to the highest, the odds ratio for all-cause mortality is 1.9[1]. In other words people with low vitamin D are almost twice as likely to die as those with high vitamin D.

That means that at least from an association standpoint, vitamin D deficiency is as predictive of poor health as smoking vs. non-smoking status.[2]

Imagine the existence of a health intervention that is just as effective as stopping smoking, that consisted of a $0.10 pill taken once a day. It's worth shouting from the rooftops.

Now there are certainly reasons for apprehension. And of course correlation does not always mean causation. In particular supplementation does not seem to directly lower mortality. However sun exposure does seem to directly lower mortality. That suggests the possibility of an unidentified sub-type of vitamin D or other micronutrient related to sun exposure that is driving lower mortality. (In which case serum vitamin D would be acting as a proxy for sun exposure.)

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4103214/ [2] https://www.ncbi.nlm.nih.gov/pubmed/22688992

Personally I care about it because I have been diagnosed with VD deficiency, as my blood VD level is only half of the minimum healthy one. It makes sense since I am always inside.
As a layman observer of the scientific debate, the Vitamin D guys have been quite persistent about the correlation between Vitamin D levels and deaths. Is there causality? Beats me. The best I've heard by way of explanation is that inflammation depletes Vitamin D stores. That idea is usually followed-up with the additional theory that CV-19 causes inflammation and high platelet activity, clogging up small blood vessels and producing most of the major effects that are observed.
As with many comments in this thread, carefully reading the originally linked review: http://agingbiotech.info/vitamindcovid19/ would help. One of the 3 recent preprints specifically noted repeated testing of C19 patients and they did an ANOVA statistical test and determined that D blood levels were not declining in the patients over the course of the infection.

This doesn't prove causality, but it rules out the reverse causality you hypothesize in this post. There is a good, concise (3-paragraph) sub-section on the causality question in the discussion section called "Correlational data supported by many pieces of causal evidence". Mandatory reading for anyone who reacts with "correlation doesn't imply causation" as a criticism. Karl (author of the review)

I'm surprised it hasn't cured cancer...yet
Sure, being healthy on many levels seems to be the best offense against C19 and lot's of other things.
If this is right, it means there's a natural non-intervention-based treatment for COVID called "going outside and getting sun."

What a concept. Positively medieval!

Funny how you don't see many doctors or pharmaceutical companies trumpeting this new treatment as a part of a treatment regime.

Obviously there are second order social-benefits to staying at home, but it's just funny that so little attention has gone into something as simple and reasonable as 'get more sun' compared to the billions spent on equipment, drugs, and hospitalizations.