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Vitamin D deficiency and Covid-19 mortality [pdf] (borsche.de)
360 points by black6 on Aug 5, 2020 | hide | past | favorite | 256 comments

I've mentioned this before, but my wife is a parathyroid surgeon (parathyroids are the glands that regulate the calcium in your neck) and would beg you to PLEASE monitor your calcium levels if you are supplementing with Vitamin D. She often sees patients on high doses of Vitamin D from well intentioned doctors, but with out of whack calcium levels because of it, and the patients can be very sick without understanding why. Often their doctors don't understand the processes either which is why they end up with her. I'll have her write a blog post about it at some point, but it is a real risk with possible severe long term consequences and she sees it a lot more often these days. She is getting her blog kicked off here (just yesterday actually) https://devaboone.com if you want to follow along.

Would you mind elaborating on what you mean by "wacky" levels? I can't tell from your comment if that means high or low. Asking as a Vitamin D supplement user who uses 2-3k IU a day

Hi, I'm the wife. High dose Vitamin D can cause elevated calcium levels (meaning over 10.0 mg/dl for adults over 40, it can be a little higher for younger adults). I usually don't see that occur with doses at 2-3 K IU daily. You can also check your Vitamin D 25-OH levels (the level that will be done if you just get a standard "Vitamin D level") and these should be in a reasonable range. What constitutes reasonable may be debatable, but in general I do not see elevated calcium levels with Vitamin D levels that are under 50 ng/ml (unless the person has parathyroid disease, another topic). The "toxic" range for Vitamin D is usually set to 100, but this is well over where most people should be. Toxicity with regard to Vitamin D means high calcium - that is the toxic effect. And I have seen this toxic effect occur with Vit D levels in the 50s.

Would you still consider 5,000 IU of Vitamin D per day safe as far as these calcium issues go?

I had a doctor tell me to take that dose for at least a few months a few years ago after low levels in my bloodwork during the winter. But I've never known if I should lower the dose to take on a continuing basis or adjust during the summer when I get a little more sun (but I still work in an office/at home so spend a lot of time indoors, especially now).

I do see people get high calcium levels after being on this dose for years. But not always. You may be able to handle that dose. If you are getting "routine" labs done, then there is likely a calcium level in there. If your calcium is normal (under 10.0 mg/dl for adults over 40, younger adults can be a little higher), then your Vitamin D dose is ok... but I would still recommend coming down a bit on that dose. It is a high dose, and Vit D builds up in your body, since it is a fat soluble vitamin.

Curious on your thoughts/experience with dosing w/ co-factors wrt to calcium levels (for patients, have you been tracking these?)

Specifically, Vitamin K:

Ballegooijen, Adriana J. van, Stefan Pilz, Andreas Tomaschitz, Martin R. Grübler, and Nicolas Verheyen. “The Synergistic Interplay between Vitamins D and K for Bone and Cardiovascular Health: A Narrative Review.” International Journal of Endocrinology 2017 (2017). https://doi.org/10.1155/2017/7454376.

And Magnesium:

Uwitonze, Anne Marie, and Mohammed S. Razzaque. “Role of Magnesium in Vitamin D Activation and Function.” The Journal of the American Osteopathic Association 118, no. 3 (March 1, 2018): 181–89. https://doi.org/10.7556/jaoa.2018.037.

I'm also curious on your thoughts on what you consider high for supplementation, vs say sunlight exposure, as a single MED of sunlight exposure is equivalent to about 10-25K IU of oral supplementation.

Engelsen, Ola. “The Relationship between Ultraviolet Radiation Exposure and Vitamin D Status.” Nutrients 2, no. 5 (May 4, 2010): 482–95. https://doi.org/10.3390/nu2050482.

On the flip side, I've seen that in a recent RCT, that recommended sun exposure guidelines were not sufficient in reversing deficiency:

Lee, Yu-Mi, Se-A Kim, and Duk-Hee Lee. “Can Current Recommendations on Sun Exposure Sufficiently Increase Serum Vitamin D Level?: One-Month Randomized Clinical Trial.” Journal of Korean Medical Science 35, no. 8 (January 22, 2020). https://doi.org/10.3346/jkms.2020.35.e50.

A couple of questions if you don’t mind.

What are your thoughts on the research about low Vit D being caused by inflammation as opposed to the reverse?

Also any thoughts on what form of testing works? Seems like many things tested often have variations that are not routinely tested for.


My autoimmune disorder was initially diagnosed via positive responses to antibiotics. Normal testing confirmed it later on, so I’ve been highly interested in some of these unusual approaches.

just checked my "Vitamin D, 25 OH" test:

result: 13.3 ng/ml, normal range: 25.0 - 80.0 ng/ml

I'm taking Vitamin D3 Max 125MCG per day, is this "overdose"?


Since the doc hasn't replied to this question (yet), your Vit D levels are low enough to warrant supplementation. In my country it is common to supplement with 60K IU once a week, for 8 weeks, before moving to a maintenance dosage of 60k once a month. That's almost 10k IU/day during the loading phase. You're at 5k IU/ day, so should be fine. In comparison, a fair skinned person at the beach on a sunny day will make over 10k IU of D3.

Thank you!!!

The Harvard Gazette:

Study confirms vitamin D protects against colds and flu


This is entirely anecdotal, and I don't have an expert's opinion on this, but I believe I was suffering from Vitamin D toxicity. I had been taking 5000 IU/125 mcg of Vitamin D3 daily for several years, and one day I started experiencing painful and distressing heart palpitations. They persisted on and off for months, until at one point near the beginning of quarantine I ran out of Vitamin D supplements. I went a few weeks before buying more, and during this time I didn't have any heart palpitations, though I hadn't really noticed until after I started taking Vitamin D again, at which point my heart palpitations restarted immediately. I stopped taking Vitamin D and haven't had any heart palpitations since (several months now). My working hypothesis is that the Vitamin D supplements were causing heightened blood calcium levels, which was messing with my heart.

Fairly likely you are magnesium deficient...magnesium is a critical cofactors to vitamin D and even moderate D3 intake can trigger symptoms such as muscle cramps and heart rhythm changes. Unfortunately no easy way to accurately test a magnesium level, as it’s mostly intracellular and blood tests are pretty much useless

Possible, but I think unlikely. These days, my diet mainly consists of Soylent and Vite Ramen, which together provide me with 105% of my DRV of Magnesium in the form of Magnesium Phosphate and Magnesium Gluconate, respectively.

Looking at the nutritional info for Soylent and Vite Ramen shows that they also contain Vitamin D - at the same DRV percentages.

If you're getting 105% of your magnesium from these items, then you're also getting 105% of your Vitamin D before taking any additional Vitamin D supplements/sun exposure.

Adding the 5000IU of Vitamin D3 would be increasing your intake to 5840IU (730% of DRV) - assuming you didn't ingest anything else fortified with Vitamin D.

Not a single person knows what optimal Vitamin D or Magnesium means for the population or for you individually. So it’s very difficult assumptions here, even with testing genetics plays a huge factor.

Great answer, thanks. So measuring blood levels of vitamin D and setting a specific target no higher than 50 ng/ml should be enough to avoid this problem for most people? Or could taking a high daily dose for a short time to get to the desired blood level cause trouble as well?

Finally, do you see much difference in getting to that high blood level of vitamin D from sun exposure vs D in diet (fish, etc) vs supplements?

I recently started trying to get more vitamin D from the sun, a sperti vitamin d lamp, and food, in order to reduce the amount of pills needed for a given IU. I use the dminder app to track estimated blood levels between tests.

Some people can tolerate Vitamin D levels above 50, so I wouldn't set that as an absolute cutoff - a Vitamin D in the 50s is good for many people, but I definitely don't want to see it above 70. Taking a higher dose for a short period of time is completely acceptable, as long as it doesn't become something that you stay on for years. It is really hard, if not impossible, to get toxic levels of Vitamin D solely from the sun or diet. I only see it with people taking supplements. And usually it's not a low dose of supplements. (And actually, many people don't even realize that they are getting high doses of Vitamin D. It is added to a lot of vitamins and supplements - so that supplement you take for hair growth may contain a few thousand units of Vitamin D, for example. I ask everyone to get out all of their supplements and look through for vitamin D.) In general, getting vitamins and minerals from diet is preferable to getting from supplements.

Sorry about the rate limiting! That's a new-account issue, and I hate that it affects perfectly legit new accounts. I've switched that off now, so she can post freely. If you'd like, we can transfer your comments beginning "From devaboone" to her username. (Edit: done now, by permission via email. The parent comment was originally posted by conorh.)

(All: when you see issues like this affecting HN threads and feel like doing a good deed, please alert us at hn@ycombinator.com. We see all the emails but often have no idea what's going on in the threads.)

Some of comments show up on the thread but not necessarily on her comment history.

I'm not seeing that. Can you link to an example?

Actually I think I was mistaken. They were more recent comments posted on an older comment by someone else, so they show up further down in her history.

What is a “not low dose” of vitamin D? Would 5000iU a day still be low? 10,000iu?

Is it really possible to have enough vitamin d exposure just from diet for someone who lives in a northern state which doesn’t get nearly as many sunny days as a place like florida or california?

5000 IU is high dose. 10,000 is really high. A more moderate dose would be 1000 to 2000 daily. If you live in a northern state, your Vitamin D level will vary with season. And with increased use of sunscreen (which is a good thing), it can be hard to get enough Vitamin D. I'm not opposed to anyone taking Vitamin D (I take it actually). I just want people to take it in moderation unless there is a very clear reason for taking high doses (and there are indications for that).

My wife and I take 60000 IU twice a month. Not as a daily dosage. Would this still constitute as high dosage? We don't get a lot of sunlight here, and we don't step out that often these days.

What is the current scientific consensus on how to take Vitamin D? Daily doses? Single very large doses spaced every fortnight?

I've tried searching the internet before about Vitamin D and it's surprisingly confusing, both about dosage as about intake routine. Also confusing that daily requirements are contested to be way off to our real needs, it's just a lot of misinformation lingering around that I, as a layman, can't really parse it.

The supplements with 10000 IU are very common these days... now you scared me..

If taking Vitamin D do you recommend Magnesium and K2 as well, as I understand it these need to be in balance?

I don't know if K supplementation helps with calcium levels, but you don't need magnesium supplementation as long you have half-decent diet.

There is plenty of magnesium in foods.

It's true that there's magnesium in everything, but the definition of half decent diet becomes rather strange in the light of a recommended intake for adults.

Men are recommended a bit over 400 mg magnesium per day.

Black beans are quite rich in magnesium, but you still need to eat more than 3.5 cups of it to get the recommended daily amount of magnesium, or 5 cups of cooked brown rice, spinach? That's 2.5 cups of boiled spinach.

Generally, if you eat between 5-10 cups of solid food each day, you are fine no matter what you eat. But that's a lot of food unless you have a very physically active, job.

It used to be mostly true, when most people had physically demanding jobs, it's not true any more.


"National Health and Nutrition Examination Survey (NHANES) of 2013-2016 found that 48% of Americans of all ages ingest less magnesium from food and beverages than their respective EARs; "

Does this material affect your advice?


No, it doesn't. I haven't had a chance to really critically review the studies that are cited in that article, so I can't give an in-depth answer as to why that article is wrong. But I know that my recommendations are based on patients I have treated. And I have treated thousands of patients with parathyroid, calcium, and Vitamin D problems. That is all that I have done for the last 6 years, in fact. I've never had a patient require 8000 units of Vit D daily to get to a normal level - never. Yet this article would have me believe that 98% of people require over 8000 units to get Vit D in the normal range?! That is absurd. Anyone who has prescribed Vitamin D and watched levels knows that this isn't true. Many things published in medical literature are not valid, and not reproducible.

This study was based in Finland where they get very few hours of sun for a large part of the year.

I just spent a few minutes surfing her blog, and she actually has a really good answer to questions along the lines of "What do you think of study X?": https://www.devaboone.com/post/evidence-and-intuition-in-the...

No affiliation, not a doctor, etc., just thought this particular essay was well stated.

What about 60,000 IU/week for someone who had D,25-OH at 7. I did that for a few weeks. Now I am up to 44 and switched to monthly. It's a singel 5ml dose. You just drink it once instead of taking it every day.

Can you expand on what constitutes the "toxic" aspect of this, i.e., the danger, symptoms, consequences?

Thanks for coming here to share your expertise!

What are the ill effects of elevated blood-calcium levels? Is there a way to avoid the bad effects of high dose Vitamin D supplements? Thanks!

There's a range of symptoms, but with me it caused (or at least contributed to) a calcium oxalate kidney stone. Not fun.

Hi, I had a thyroidectomy and was told I lost at least one parathyroid in the process. Now my hands and feet are likely to fall asleep and I have low calcium levels (relative to lab standards). Would high vitamin D + calcium citrate be good for me? And should I see a specialist or am I okay just seeing a normal endo once a year?

Hi; is there anything documented about the following effect of taking high-ish doses of Vitamin D3 for a while: a tooth/jaw sensitivity appears, like you can "feel your teeth"? In the past I have used that as as signal to back off on the Vitamin D. What is the mechanism?

Do you recommend vitamin D2 or D3 supplementation?

i thought calcium was good for you. How is vitamin d causing high levels of calcium toxic?

Not a doctor, but I have had kidney stones.

The answer is a loss of calcium, so high level found in urine test: if you had way too much vitamin D, then you would start releasing the calcium from your bones.

I don't think that taking calcium supplements would help, because calcium metabolism (https://en.wikipedia.org/wiki/Calcium_metabolism) is much more complex than that.

Calcium metabolism is complicated, but there are a few things that are straightforward. 1. Vitamin D helps the intestines absorb calcium, so taking more Vitamin D can lead to more calcium being absorbed in your intestines, and thus more calcium in the blood. The excess calcium in your blood is caused by increased absorption from the intestines, not from bone release. (High calcium with parathyroid disease is caused by bone release, as well as increased intestinal absorption) 2. Taking calcium supplements along with Vitamin D will allow your intestines to absorb more of the calcium you are taking. 3. There are several reasons for having a lot of calcium in the urine. Primary hyperparathyroidism can do it, and in this case you will see high blood calcium levels also. If the blood calcium is low or normal (under 10.0 mg/dl), then you have another reason for high urine calcium.

Do you know what could be happening if taking vitamin D gives you severe headaches that last for days and gradually get weaker?

If you need more information, please ask away.

As someone who has worked on various deficiencies over the years, including vitamin D, I will suggest it means the dose you are taking is probably too high. When I had similar issues, reducing my sun exposure -- which was how I was improving my vitamin D status at the time -- resolved the headaches and vomiting that I was experiencing.

Thanks for the response. I'm surprised you can even get too much D with sun exposure. The thing is: I used to take vitamin D supplements fairly regularly, but now I barely take any. I will go weeks without supplementing, but when I do, I get headaches. No increased urination though, which would happen if i had excess calcium, and no nausea/vomiting.

Last time, i tried 5000IU, but this came after weeks of not taking any D supplement, and I've not taken any since. My reasoning is: that would effectively make the average dose < 400 IU, so shouldn't give me any problems, yet it does. Maybe I'm getting more from the sun than i realize :/

I'm surprised you can even get too much D with sun exposure.

I'm a special case. Trying to explain that is probably a can of worms.

shouldn't give me any problems, yet it does

There may be other factors there, which I could potentially speculate on. But A. It tends to be a can of worms when I start speculating like that and B. You didn't initially give enough info to really warrant such speculation. You only gave enough to make me feel like the safe bet was to comment on the dosage and leave it at that.

I understand. Thank you :)

I recently stopped taking my (self-prescribed) dose of 1,000 IU Vitamin D3. Before this I was on 2,000. I work all day and rarely leave the house, sometimes for a couple of weeks. I thought I was doing the sane thing.

A good number of months in and I start getting all of the symptoms - lethargy, constipation, stomach and intestinal pain, urinating very frequently and feeling like I had a kidney infection.

Bloods came back all normal, including vitamin D and calcium. My symptoms chime so much with Vitaminosis D (Vitamin D toxicity) that I wonder whether the serum levels are accurate indicators of such toxicity. Vitamin D is stored in fat and the calcium gets deposited in muscles - two possible mechanisms for this.

However, I do not know for sure. Either way I have been scared sh!tless of self-prescribing anything else. No matter how mundane it seems.

1000-2000IU is a low dose your blood work came back normal. All those symptoms are pretty generic as well, I'd look elsewhere.

It seems that you have to balance it with Vitamin K2


Thanks for the link and please have her include whether k2 supplementation is recommended or necessary along with the d3. I have been supplementing with k2 due to a history of kidney stones.

Could you elaborate in more detail? Given your wife's background, I'd guess you were referring to people with pre-existing hyperparathyroidism who are therefore prone to quickly develop hypercalcaemia from even modest Vitamin D supplementation, but perhaps there's more to it?

If your wife wants to write a blog post on the subject, I'm sure there'd be a lot of interest.

She was thinking about writing a blog post on Vitamin D already and she says she will it in the next few days and I'll post it here when she does. She is not talking about patients with pre-existing hyperparathyroidism - they often think they have it because the calcium is high, but it is only high because of the vitamin D!

You/she should put an email signup on her site or in a comment here. Would help people see the eventual article.

There are great questions on this thread, when she is available she will weigh in. I don't have the answers unfortunately! Feel free to reach out to her via her website too if you have very specific questions - she doesn't mind that at all.

Thank you. Somewhat related: I wanted to inform that ublock hides the submit button on the blog - if someone is having difficulty subscribing, they should trying disabling ublock for a bit before the submit button becomes visible.

Right now, I'd rather have a calcium problem than a Covid-19 problem. Also, some of the studies being thrown around in this discussion have mentioned that safe levels of Vitamin D are much higher than a lot of medical professionals actually think.

> there is virtually no risk of toxicity in supplementing up to 10,000 IU of vitamin D3 daily


I read the study that is cited on your link. It was a review article about Vitamin D, not a study on Vitamin D toxicity. And in fact, in the references for that article, there is no study cited directly related to Vitamin D toxicity that I can see. The cutoff at 10K is largely someone's opinion. I cannot say how many people will be harmed by taking such a high dose, but I know with certainty that toxicity at that dose is not rare, because I see it all the time. Some people can take very high doses and be just fine, calcium stays normal. Others will take 5000 units daily and end up with high calcium, and all the symptoms that go along with that (including kidney stones, fatigue, cardiac arrhythmias, etc). Now I am not saying that NO ONE should take high dose Vit D. Some people actually need that high dose, but that is only in the case of someone with very low Vit D and low calcium levels - often in someone who has problems with intestinal absorption, as you would see in someone who had a gastric bypass, for example.

Thanks for the response. I'm curious what your wife thinks about this article [0], mentioned elsewhere in this discussion. It makes the case that the current RDA for Vitamin D is based on a statistical error, and that the recommended dose should be closer to 8000 IU for young adults.

[0] https://pubmed.ncbi.nlm.nih.gov/28768407/

Not OP, but with vitamin D the dosage is actually something you can figure out empirically by testing vitamin D levels and taking supplements.

No one who talks about supplementation seems to think a level of 8000 over a long period is necessary to obtain adequate levels.

I think by the same token the recommended supplement level of 600 IU is inadequate to reach a sufficient level. But the paper in question didn’t test their result empirically.

Correct. It's fairly easy to know whether the dosage you are taking is working, since you can check levels. 8000 units is a really high dose, one that I have never had to give. The article suggests that 98% of people require that much to get to normal levels, which is almost laughable.

8000?? EFSA recommends a reference value of 1000 IU. And a tolerable upper intake level of 4000 IU.

FYI, that is the wife/doctor's account you replied to.

dang switched a lot of the comments to her personal username after the fact.

I'm also hesitant to take medical advice from a new account on an internet forum who is disputing medical research. Definitely not saying anything fishy is up, just that we should keep things in perspective.

What level of supplementation? I see huge ranges of vitamin D, by mouth or intramuscular, mentioned in this thread. As someone taking vitamin D (1k IU) with K2 I wonder what levels affect calcium.

All the vitamin D supplements I see in the pharmacy come combined with calcium. Should that take care of it or does "out of whack" mean calcium could be too high as well as too low?

Calcium supplements often include Vitamin D because it aids in intestinal absorption of calcium. That is actually one of the main roles of Vitamin D. You can find Vitamin D by itself, in anywhere from 400 to 5000 units per pill. Taking high doses of Vitamin D can cause high calcium (due to more being absorbed in the intestines), and taking extra calcium would just exacerbate that. If someone has low calcium levels, I recommend taking both calcium and Vitamin D. Low Vitamin D can cause low calcium levels.

Here (below) is a quote from the article, on the subject of calcium. (I suppose some of us may be reluctant or unable to have calcium levels monitored. But it seems all of us should be taking vitamin K2 along with our vitamin D.)

>The authors explicitly point out that each vitamin D supplementation must be accompanied by sufficient vitamin K2. This certainly prevents the rise of the calcium level in the blood, which is often seen as a risk for the supply of vitamin D

Vitamin K2 does help bones absorb calcium, but it will not prevent the blood calcium level from rising if you are really taking more Vitamin D than you need. This is simply wishful thinking.

A vitamin K deficiency with normal vitamin D levels would cause blood calcium levels to rise. Many people are deficient in vitamin K since it's mostly found in leafy greens and liver, no one's favourite foods. The difficulty is judging what is a normal vitamin D level by incidence of people with elevated calcium levels in the blood without having tested all of those people for vitamin K deficiency first.

Is there a way to determine if I'm deficient in Vitamin K2. If yes, is there a way to get supplements for it?

Is vitamin K safe to supplement? Or does it mess with the blood clotting?

People recommend really quite doses: K2-MK7 at 100 to 200mcg, or alternatively K2-MK4 15 to 45 mg (not mcg).

Fermented foods are a potent source of bioavailable K2

Is it true that Vit K2 ameliorates that problem? Or should that also not be taken blindly?

Without a reference to go by a quick Google indicates toxicity is only likely by taking far above recommended levels (max recommended is 4000iu daily) for an extended period.

Presumably people on those kind of doses are taking it under medical supervision, or are idiots/under the control of idiots.

I am not a doctor, but without further information it seems that as ever, following the guidance on legit supplies specifically and mainstream medical advice generally is a good rule of thumb.

There are some very vocal people who argue that the risk of toxicity is very low. The studies aren't great. But for most people, taking a moderate dose of Vitamin D will be safe. Unfortunately, I have treated many patients who come to me with high calcium levels due to taking Vitamin D. They do not have parathyroid disease (I have treated thousands of patients with parathyroid disease). They have simply been taking high doses of Vitamin D. High dose is generally 5000 units a day or more, though I have seen it occur with lower doses if taken over many years. Vitamin D is fat soluble, so it will stay in your system for a long time, building up. Of note, some of those patients were instructed by their doctors to take those high doses. Even doctors forget the relationship between calcium and Vitamin D, and I have spoken with doctors who did not realize that 5000 units a day could cause problems. As a doctor, there is a lot to know and remember, and most doctors haven't studied calcium metabolism in many years.

It makes sense many doctors, especially general practitioners, would forget or not know about the Vitamin D/Calcium link. However, wouldn't a doctor prescribing a large dose of Vitamin D take at least yearly standard set of blood tests too that would include calcium levels? Then again, that's assuming there's a fairly standard set of blood tests to check for imbalances of this kind. Also, it seems odd there isn't a standard procedure for prescribing Vit D that included "check calcium levels".

A large dose of vitamin D may not show up in the bloodwork for years if the patient keeps a fatty enough diet.

Would you mind telling us what the medical literature says about deaths from Vitamin D overdose? Around how many people in total have died from taking too much Vitamin D?

It is difficult to die of a Vitamin D overdose, though not impossible. Here is what happens: Vitamin D increases calcium absorption from the intestines. Over time, if you are taking too much Vitamin D, your levels can get very very high over time. Vitamin D is fat soluble, so you don't just "pee it out" like some water-soluble vitamins. It stays in you long-term. Eventually your calcium will rise. It can rise slowly, but you will get symptoms. Common symptoms would be fatigue, brain fog, insomnia, headaches, and kidney stones. If you are at levels where you could potentially die from Vitamin D overdose, your calcium levels will be high enough that you will feel acute symptoms of markedly elevated calcium: like vomiting and confusion. Someone will end up taking you to the hospital, because you will become unconscious. At that point you will be given IV fluids and the calcium will drop. You could die, especially if you have other health issues, but more likely it would be treated and you would get released. The effects of Vitamin D toxicity are related to the high calcium levels that it causes.

Do you test for vitamin K defficiency before taking the patients off vitamin D supplements?

Thanks for the reply and contextual information.

I've seen mention that the risk of overdose at 10,000iu daily is still very slow.

Although this is a notable finding it's important to remember that it doesn't lead to the conclusion that supplementing vitamin D will be very beneficial here. When vitamin D is produced in the body naturally via exposure to sunlight there's a huge amount of other things that occur as well, and we don't have a ton of good science to back up if curing a vitamin D deficiency via supplementation of pure vitamin D is really nearly the same as getting it naturally, which is a common problem for supplementing things and nutritional science and epidemiology in general.

The extent that covid harms those that are metabolically unfit in many different ways much more than those that are perfectly healthy is still pretty under-discussed imo though, and this is yet another good data point in favor of it, even if Vitamin D is much more of a different proxy than some of the other large correlations we see with covid mortality.

What about this section of the pdf? From a 2016 study on patients with other respiratory diseases.


High dose vitamin D administration in ventilated intensive care unit patients: A pilot double blind randomized controlled trial In the study, patients with vitamin D deficiency (<20ng/ml) were divided into three groups: A placebo group, and two groups that were given different doses of vitamin D. The single administration of 250,000 IU of vitamin D was compared with the single administration of 500,000 IU of vitamin D by injection. In addition, the vitamin D levels were increased to 45 and 55 ng/ml, respectively. While the length of stay of the placebo group at the ICU was 36 days, the 250,000 IU group averaged 25 days and the 500,000 IU group averaged 18 days. This is a smooth halving and means that vitamin D is useful not only in prevention but also in acute cases.



Ah, the pdf has a second such study. Mortality almost half less


Intervention was carried out intramuscularly with 300,000 IU of vitamin D. Instead of 28 days only 18 days mechanical ventilation, instead of 29 only 19 on ICU, instead of 61% deaths only 36%.


Also see this letter by Dr. Gerry Schwalfenberg. It's just an anecdote but his claim of success in treating influenza patients with a "vitamin D hammer" is interesting and should prompt additional research.


Total anecdote, but I’m prescribed 50k IU of Vitamin D 3x weekly.

However, that’s a bit hard to remember so I always have extra on hand. When I have a cold coming on a take a large(r) dose and it certainly seems to help.

I haven't seen that one, that looks pretty impressive, especially for administering it in a single dose that is that large. That's definitely a good data point in favor that some of it is direct causation though.

31 total subjects, only 13 vitamin D deficient initially, p = 0.03. This study at best suggests further, more rigorous research here may be warranted. It says nothing about causation, for all that its authors seem to feel otherwise - and that they feel otherwise suggests its results should be taken with more than the usual amount of skepticism.

Have a look at table 1. Only 5/31 subjects had “sufficient” vitamin d. In between deficient and sufficient there is the insufficient category, from 20-30 ng/ml.

Though I agree further study is warranted. The highest vitamin D group actually had the highest mortality after 84 days. Though this group also had the most pre-existing heart conditions by far, so that could account for it.

Ah, there was a second such study in the pdf. Mortality down by almost half.


Intervention was carried out intramuscularly with 300,000 IU of vitamin D. Instead of 28 days only 18 days mechanical ventilation, instead of 29 only 19 on ICU, instead of 61% deaths only 36%.


More studies referenced here, also showing ~55 ng/ml being optimum for maximum health benefits. The current recommendations are way below that. Well worth to watch the whole video:


Those dosages are far higher than anyone supplementing vitamin d are likely to take.

I found out on HN that the official daily recommended dose for vitamin D is flawed, it was based on an erroneous statistical analysis. [1] contains some details. The bottom line is the daily dose should be about 8000 IU rather than the official 400 IU.

Obviously, 250000 IU or 500000 IU is much higher, but this is a one-shot, not a daily dose. If you take 8000 IU daily dose as correct, then those 2 megadoses correspond to a one month or two month intake. Very high indeed, but not absurd

[1] https://pubmed.ncbi.nlm.nih.gov/28768407/

When that came out a few years ago [1], I began getting my vitamin D tested through my doctor and slowly ramped up my dosage. It went from 28 ng/mL (70nmol/L) [2] to 32-35 ng/mL (80-87.5 nmol.L). In my own physiology, this required 4,000 IU (100 mcg) daily, orally. 2,000 IU was not quite enough.

I'm going to add another 2,000 IU daily to see if I can reach the recommended 100 nmol/L from the OP. [3]

[1] https://news.ycombinator.com/item?id=15867918

[2] converter here: https://www.azcalculator.com/calc/vitamin-d-ngml-nmolL-conve...

[3] https://pubmed.ncbi.nlm.nih.gov/28768407/

Now, there is a difference between "ramping up" levels and maintenance levels, right?

It's generally been found that larger doses are required to move the blood levels up, but it doesn't seem like people need to remain at those dosages to maintain those levels.

A few things.

Whenever your conclusion is that the "official recommendations are flawed", and those were in place for a while now, scrutinize your process. Reading a post on social media is rarely paradigm-changing - and when it is, it's overwhelmingly in the wrong direction.

Secondly, the 8k dose doesn't seem realistic historically. Is there any diet that does not include the products of modern tech, that gets anywhere near those levels consistently? Doesn't seem likely.

Megadoses of anything are not without issues. There will be side-effects with vit D, esp. related to calcium, etc.

The data on the possible connection between vit D and respiratory illness is still way more sketchy than most people assume. There is no solid research yet.


That being said:

Vit D deficiency is pervasive in a lot of places. Most people would benefit from taking some supplementation.

1000 UI capsules are cheap and readily available. That dose is not far from the various "official" recommendations (which are all over the range of the hundreds, depending on country). There are no known side-effects at that level.

> Secondly, the 8k dose doesn't seem realistic historically. Is there any diet that does not include the products of modern tech, that gets anywhere near those levels consistently? Doesn't seem likely.

Because historically most vitamin D intake didn't come from diet, but from sunlight exposure. Varying widely depending on how much skin you're exposing, the color of your skin, latitude, season, etc., estimates of vitamin D hourly vitamin D synthesis can be on the order of tens of thousands.

Diet wise no. Skin production wise, yes. Though these are different mechanisms and the body can turn off vitamin d production from the skin past a certain point.

They’re single use doses. These are often used by doctors to treat severe deficiency, e.g. weekly 50,000 UI.

It is plausible that in an ICU situation with limited time a single, even larger dose makes sense. For an individual not critically ill, more gradual daily boosting of vitamin D is possible. The ICU patients didn’t have this time.

What's the LD50 for vitamin D?

You experience issues with hypercalcemia long before the ld50 becomes an issue if you plan on supplementing too much

I'm thinking of a single megadose scenario.

Wow that could be a game changer. I’m surprised I hadn’t heard about that.

It's frustrating that when this comes up, this comment is always the top one, because it's not true.

We have dozens of RCTs suggesting that vitamin D supplementation prevents respiratory infections[1]. There is a very good chance people could mitigate C19 risk with supplementation.

And I personally trust the vast majority of people to use reasonable enough dosing that overdose is unlikely, especially with appropriate messaging.

Downplaying the risks of low vitamin D (way more prevalent than vitmain D toxicity) seems as dangerous as the early pandemic messaging in the US that masks are ineffective.

1. https://www.bmj.com/content/356/bmj.i6583

Dr. Rhonda Patrick on "Vitamin D may reduce susceptibility to COVID-19-associated lung injury": https://www.foundmyfitness.com/episodes/vitamin-d-covid-19

In Finland we put Vitamin D in milk that’s sold on normal shops. And taking a supplement is heavily recommended.

Though this is mostly because for 6 months of a year one simply cannot get it the natural way (too cold and sun is too low). And thanks to this we don’t have much deficiency, long time ago we used to have.

Not saying it means it would help with covid. But the supplements definitely help with deficiency in a way that does cure/prevent rickets.

In the USA we fortify milk with Vitamin-D too, but only a small amount - each 8oz cup (240ml) has 15% (3mcg) of your recommended daily allowance.

There's research that suggests that the RDA is way too low, plus many adults don't drink a lot of milk, certainly not enough to make significant impact on their vitamin-D intake.



The last time I looked into this what I got was that there'd been a statistical error made in the process of determining the RDA, and it was just never corrected. The RDA is the amount that guarantees that only a certain fraction of the population has a deficiency, if everybody eats that much, but they calculated it so that only a certain fraction of population studies would find a deficiency on average. Furthermore, dietary vitamin D is absorbed rather poorly, so the amount of it you have to eat is immense compared to going out into the sun, resulting in really high "recommended" RDAs---it's the blood concentration divided by sensitivity but the measured sensitivity is surprisingly low. [1]

[1] A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D, Paul J. Veugelers* and John Paul Ekwaru https://dx.doi.org/10.3390%2Fnu6104472

Also, isn't milk consumption unevenly distributed across the whole population? E.g. those with an Asian background I would expect to consume less milk than the population average.

True, I think food supplementation is hard to do in general since the dose needs to be appropriate for anyone that may consume it, with age ranging from infant to elderly.

>In Finland we put Vitamin D in milk that’s sold on normal shops.

I'd wager it's the same in all the Nordic countries, at least it's the same here in Sweden.

A couple a months ago when I spoke to my dad, he told me he had a checkup because he had been unusually tired, turned out that the only thing the testing showed was that he had d-vitamin deficiency.

What surprised me is that he was given prescription d-vitamins, since you can buy them anywhere without prescription.

You can get larger doses of vitamin D in one pill as a prescription. Like 20000 IU once every week or two instead of daily.

Also there is vitamin D2 and D3. The normal stuff you take is called D2. The D3 is made by the kidneys from converting D2. But those with certain diseases, the kidneys don't do the conversion so they provide vitamin D3 in the form called calcitriol. Its something I need to take due to my kidney failure.

At least in the UK, it's pretty easy to get D3 over the counter too. I've been buying D3 drops off of Amazon.

Looks like I misunderstood it. Calcitriol is different from D3. Normally your body converts D3 to calcitriol but those with certain diseases will not get it converted.

Calcitriol is actually the most confusing of my medications to manage since the dosage needs to be adjusted based on monthly blood tests. Things like amount of sun exposure can swing my numbers around. And it interacts with so many blood test numbers like PTH, phosphorus and calcium levels.

My wife was given these, during the early part of her pregnancy. I too, was surprised that they came via prescription.

The dosage did work out to be 50x what was in the standard products though.

UK government changed it's advice to recommend supplementation in the winter months (unsurprising given how far north the UK is).

You had a very limited coronavirus outbreak it seems. Does Norway have the same vitamin D supplementation policies? Their outbreak was similar in size to Finland’s.


Edit: Interestingly, the source pdf notes the nordic countries have higher D3 levels than Mediterranean countries. And speculates this may help explain lower incidence up north.


The researchers around Petre Cristian Ilie have tested the number of Covid-19 deaths per 1 million inhabitants against the vitamin D level in 20 European countries and come to the following conclusion: The mean vitamin D level in the countries studied (mean 22.4 ng/ml, StDev ±4.24) correlates strictly with the number of Covid-19 infected per million population (mean 295.95, StDev ±298.73, p=0.004) and with mortality (mean 5.96, StDev 15.13, p<0.00001) The death rates in Spain and Italy are much higher than in Scandinavia. The researchers explain this with the statistically significant higher vitamin D level among the inhabitants of the Nordic countries: The study shows that in older people, the average blood vitamin D level in Spain is 10.4 ng/ml, in Italy, 11.2 ng/ml, while in the Scandinavian countries it is 18 ng/ml. The northerners obviously do have the better vitamin D levels, although the sun is not as intense there as in the south. This could either be because they are more active outdoors or because they get more vitamin D from food, e.g. fish, or both. Fat sea fish contains a lot of vitamin D. And southerners tend to spend their midday hours in the shade or indoors. Shadow, window glass and a longer way through the atmosphere (morning/evening, autumn/spring) reduce UVB radiation much more than UVA.

Norwegians worship the sun when it is present and they drink more milk as adults than in other non-Nordic countries. The milk is vitamin D supplemented. Sunbeds have become unpopular recently (3 years ago there were 3 tanning salons in walking distance of me now there are none).

The reasons that the outbreak has been minimal so far here are more complex though. Norwegians natually socially distance. The joke goes, "I am glad the lockdown is over and we can go back to the usual 5 meters - having to stand 1 meter from people was too close". Basically avoiding people for a few weeks was quite easy for many Norwegians. Younger ones tend to live in one bed flats rather than flat shares. Young people don't visit their parents and grandparents as much as they probably should. Also people buy into society and trust their government here. The PM announced a crisis and most people followed the guidelines for several weeks. Compliance dropped after a few weeks but it was clearly sufficient to break the infection chains.

What's the amount of Vitamin D supplementation? This is common in the States, but I wonder if Norway is higher.

> In Finland we put Vitamin D in milk that’s sold on normal shops.

Historically, the diet in that region included fish and other foods rich in vitamin D. I'm not sure what's the typical diet like these days.

But yeah, up north you definitely need to increase the intake of vitamin D. Same as Alaska in the US.

One effect of sunlight exposure is to stimulate production of nitric oxide, which lowers blood pressure. Hypertension is one of the most common comorbid conditions for COVID-19 deaths. I don't know if there's a causal relationship but it could be worth further research.

That's interesting. Do you have pointers to relevant research?

> Although this is a notable finding it's important to remember that it doesn't lead to the conclusion that supplementing vitamin D will be very beneficial here....we don't have a ton of good science to back up if curing a vitamin D deficiency via supplementation of pure vitamin D is really nearly the same as getting it naturally

I don't know what you mean by 'a ton', but there is good evidence that Vitamin D supplements do provide much of the same benefit [0] [1].

> Ultraviolet radiation (either from artificial sources or from sunlight) reduces the incidence of viral respiratory infections, as does cod liver oil (which contains vitamin D).

[0] https://pubmed.ncbi.nlm.nih.gov/16959053/

[1] https://sci-hub.se/https://www.sciencedirect.com/science/art...

Technically true, but you should still eat vitamin D supplements.

It's very cheap and safe, so worst case it has less effect than you hope. You can overdose, but you have to really crazy with the dosage.

Also 1: Vitamin D supplements do cure rickets.

Also 2: All of us who eat supplements should show up in the stats as high in vitamin D, so the data does partially cover that case.

What brand/strength of VitaminD supplements do you all take?

I take NatureMade brand vitamin-D supplements.

That brand is USP certified which means their product is externally certified (through products purchased at stores) to contain the amount of supplement they say it has.

There are some other similar certification programs that you can look for when choosing supplements, but USP seems to be the most rigorous:


I registered a 5 ng/ml with a blood test. I wasn't feeling tired or seeing any negative effects at that time from it and most likely it had been low for a decade. However for obvious reasons I began immediately taking actions to move that number persistently into a healthy range.

I've been using a D3 supplement of 5000 IU from NatureWise, for several years. I take one per day depending on the time of year. It's inexpensive, ~$11-12 for a year supply, and it has worked very well. I take it daily throughout Fall & Winter, and then lighten up on it during Summer.

I take Jocko D3[1], it's $25 for a year supply. The dosage is on the high end though, it's 5000IU per dose whereas doctors recommend 4000IU per day. It's important to get bloodwork done once you take it, because if you aren't deficient on vitamin D, it can have adverse health effects if your levels get too high.


I take 5000 IU D3 a day, in a pill that combines 180 mcg of K2. K2 is important for calcium transport. My most recent tested level was 38 ng/ml. I'd like it to be above 40. I also make sure to get a lot of sun, because I think the measured benefits of D3 blood levels might be partly a proxy for sun exposure. A good resource for managing your serum D3 is https://www.grassrootshealth.net

I do similarly. The k2 because I read it can be extra important if you have a history of kidney stones.

Well and K2 is involved in transporting calcium into bone. So it helps if you are worried about your D3 supplementation altering your blood calcium levels.

Sam's Club has this really crazy-understated product (imo) that I like because it contains fish oil and 2000IU VitD in a fish gelatin capsule: https://www.samsclub.com/p/mm-fish-oil-dbl-d3-200ct-fish-gel... .

Thone 5,000 IU once per day (qd)

Yeah, agree completely. I still take Vitamin D daily, and its among my cheapest supplements, I think somewhere around 3 cents per day.

It's not that safe, not like vitamin C safe. Especially not in doses sold in pills in pharmacies around the world.

I still can't figure out the safe + effective dosage of Vitamin D.

I was taking 1,000mg a day and that didn't seem to move the needle on my Vitamin D blood work.

In recent weeks I've been taking 4,000mg/day (with K2), which is 4x what I've had pharmacists recommend.

I plan to keep that up for a couple more weeks while I'm under quarantine (recently flew from a high-risk country to a less high-risk country). After that I'll level off to 2,000mg a day.

But I'm shooting in the dark. I have no idea if 2,000mg/day or 4,000mg/day is too much or not enough.

Quick Google results:

- Mayo Clinic says "Taking 60,000 international units (IU) a day of vitamin D for several months has been shown to cause toxicity."

- news-medical.net says "To prevent toxicity, tolerable upper intake levels have been fixed for vitamin D as..." 4000 for adults.

- healthline.com says "A daily vitamin D intake of 1000–4000 IU (25–100 micrograms) should be enough to ensure optimal blood levels for most people."




Studies of pale skinned Norwegiens who go in the sun during summer show they make 10,000-20,000IU equivalent a day. Results will vary depending on skin tone and the position of the sun (lower in the sky means no vitamin D as the right wavelengths of light are not hitting your skin)


The safest way is to take an occasional test for your vitamin d levels. There are tests that you can take at home that aren't too expensive!

Yep. I work inside a lot, so I started taking 5000IU of D a day. After two weeks, I had my levels tested and it showed a level of 37. When fall comes around, and I'm outside even less, I'll probably up the dosage for a week or two, then test again. Target is between 50 and 70, so I definitely need more.

Thanks. I didn't know.

Amazon has a few options in the $50-90 range.

You prick your finger, draw a "small amount" of blood, and send it to a lab.

The order it yourself lab companies compete on the Vitamin D test, you can usually get one for $40.

This is also what I read. People please read up on vitamin D overdosing.

The study showed that supplementing (though it was injection) to between "45 and 55 ng/ml" is "useful not only in prevention but also in acute cases".

So yes... sunlight does probably way more benefits for us but supplementation if you are deficient is still showing significant effects.

Just to be clear, the study that you are quoting isn't about Sars-Cov 2. This is a quote from a 2016 paper on other respiratory diseases.

And here is the quote in context, not that this isn't about Covid-19:

"High dose vitamin D administration in ventilated intensive care unit patients: A pilot double blind randomized controlled trial In the study, patients with vitamin D deficiency (<20ng/ml) were divided into three groups: A placebo group, and two groups that were given different doses of vitamin D. The single administration of 250,000 IU of vitamin D was compared with the single administration of 500,000 IU of vitamin D by injection. In addition, the vitamin D levels were increased to 45 and 55 ng/ml, respectively. While the length of stay of the placebo group at the ICU was 36 days, the 250,000 IU group averaged 25 days and the 500,000 IU group averaged 18 days. This is a smooth halving and means that vitamin D is useful not only in prevention but also in acute cases."

The Harvard Gazette: Study confirms vitamin D protects against colds and flu


University of Colorado Anschutz Medical Campus: Vitamin D reduces respiratory infections


> When vitamin D is produced in the body naturally via exposure to sunlight there's a huge amount of other things that occur as well

Any further reading on that? On the other hand worth supplementation you don’t get the harmful uv rays.

There is no evidence that a brief daily exposure to UV rays is actually harmful in terms of all-cause mortality.

UV rays should not be considered harmful de-facto!

Overexposure to UV rays is what causes trouble.

Slathering on the sunscreen even when not necessary (like walking from point A to point B, or spending 15 minutes outside, is what causes the predominant vitamin D deficiency in the first place.

Are you sure the "predominant vitamin D deficiency" isn't caused by the prevalence of metabolic syndrome?

Personal anecdote - vitamin D supplements did absolutely nothing for my vitamin D levels.

it wasn't until I committed to getting more sunlight that my levels increased.

What was your daily IU supplementation, and how long did you supplement before checking your levels again?

I take 5000 IU daily, but also wonder if I'd do better with more sunlight instead.

I was taking 50000 IU a week. Checked multiple times over periods of months.

Hey, someone like me. I was upped to that dose 2x a week and then 3x. Now my levels are up and holding.

This article is (badly) written by un-qualified authors (two software developers). This would be enough to raise at least a few red flags on the conclusions drawn here. Has it even been peer reviewed? From a first look, there no way this work would have been published by any reputable journal.

If there is any truth in what the authors claim, the best they could do is to work with field experts and/or submit their findings to a reputable journal for review and publishing. Someone's health might be on the line following pseudo-scientific works.

Here is an old clinical practice guideline article (2011) from The Journal of Clinical Endocrinology & Metabolism talking about Vitamin D deficiency and recommendations for correcting it:


You can see that prevalence of deficiency is very high, as this other peer-reviewed study confirms:


In the first article, after correcting the deficiency, the maintenance dose that they give is: 600-1000 IU/d for children; 1500–2000 IU/d for adults; 3000–6000 IU/d for obese. As you can see that's much higher than the current RDA of 400 IU/d.

And to correct the deficiency in the first place, the dose needs to be 2-3 times higher still for 8 weeks.

So around half the people in the US need to be taking a very large dose for 8 weeks, and then a maintenance dose 4-15 times higher than the RDA.

This is all from established studies done long ago that no one has disputed. But their recommendations have yet to be implemented in a lot of places, which might be why some countries fare better than others.

> This article is (badly) written by un-qualified authors (two software developers)

Indeed the first sentence talks about "corona deaths." No qualified medical professional would write that in a paper.

Is English their first language? .de and all.

Yeah, this seems to be mostly idle speculation than an actual study... and it ignores a preponderances of additional data (like, say... COVID-19 cases in the US).

The Harvard Gazette:

Study confirms vitamin D protects against colds and flu


Vitamin D has been endlessly promoted as a treatment for many diseases due to evidence from observational studies, but hundreds of millions of dollars in randomized controlled trials have never demonstrated it to be effective for any disease except rickets.

There was just a large trial published in JAMA [1] examining its effectiveness for depression given solid observational data. It was not at all effective.

The reason that Vitamin D is associated with many diseases but is not causative for anything is that Vitamin D level is highly correlated with other metrics of health such as socioeconomic status, active lifestyle, nutritional sufficiency, etc.

We are wasting our time and money looking at Vitamin D again and again and again.

1. https://jamanetwork.com/journals/jama/article-abstract/27689...

This study used a tiny amount of Vitamin D (2,00IU/day) which is absolutely not enough Vitamin D to have any affect on someone who is deficient. Going outside in a swimsuit produces 10,000+IU equivalent. We evolved nude, outdoors.


It's not a tiny amount, probably about 40% of what most adults should be getting optimally, and significantly better than having almost no intake, which is the case for a lot of people who rarely go outside and don't eat any fatty fish.

That's fair. The RDA at 400 is tiny.

But vitamin D almost certainly does help with certain conditions. For example, I have psoriasis and can develop awful (painful, itchy, ugly) plaques on my knees and elbows, as well as painful skin nodules on the palmar surfaces of my hands and feet and dandruff. I had seen a dermatologist who prescribed some cream that sort of worked, and she recommended I expose the surfaces to 15 mins of sunlight a day. Those kind of worked, but the plaques and dandruff remained. I started supplementing Vitamin D on my own (my PCP recommended it since I'm slightly deficient), and the plaques disappeared within a few weeks. The nodules only rarely appear when I'm having a stressful time. If I forget to take vitamin D for a few days (or, in the case of the pandemic, when I run out of it and can't get a timely resupply), voila, the plaques reappear. Now that isn't a peer reviewed, double-blind controlled study or anything, but the signal is extremely strong that vit. D supplementation fixes the bulk of my psoriasis symptoms. Skepticism is warranted about all vitamin claims, but my priors for vitamin D are that it may actually be effective even when the peer reviewed research isn't out. My only caution to people is that since it's fat soluble, people should try to determine the right dose before gobbling it down.

As a psoriasis sufferer, I really appreciate your personal observation on this, even if it's n=1.

Also curious, is it possible that the 15 mins of sunlight per day was the actual cure, rather than the supplements?

No, because I never got into a consistent habit of it and just stopped trying. Either the weather wasn't suitable or the sun was in the wrong position when I had a few minutes to do it or I'd forget. The dermatologist also wanted me to face those surfaces with the plaques/nodules toward the sun, and that was never terribly convenient when I had nodules or plaques on the bottom of my feet or my knees.

There are days where I bask in sunlight and others where I'm mostly in my hidey hole (esp. with the pandemic), so nothing too consistent. My post wasn't too clear about that, but yeah, I had stopped the dermatologist treatments (other than T-Gel shampoo) prior to the Vitamin D thing.

My view is that sunlight is the confounding effect. Getting substantial exposure to the sun has many health benefits, probably including Covid resiliency, and also increases vitamin D levels in the blood. So vitamin D correlates with, but does not cause, those health benefits.

How is it even plausible that sunlight does not have significant health benefits, given that Europeans evolved to have pale skin because they lived in high latitude environments?

> How is it even plausible that sunlight does not have significant health benefits, given that Europeans evolved to have pale skin because they lived in high latitude environments?

No one is arguing that sunlight doesn’t have benefits. We just don’t know if those benefits are mediated through vitamin D (in which case supplementation could be enough!) or something else.

The recent JAMA only says that Vitamin D does not help with depression. On the other hand, it seems to be useful in preventing respiratory infections, see the following for a review of randomized studies https://doi.org/10.1136/bmj.i6583 .

Depression is a tough thing to treat. The amount of treatments that show promise, but essentially don't make a meaningful difference in RCT's is very, very large.

(Perhaps not coincidentally, placebo effects in depression are known to be large).

Quite on the contrary, scientific research is still severely lacking. There's even no sound scientific consensus on vitamin d's rda. How should we acquire it, by sunbathing or by supplementing, in a high dosis bolus or a daily small amount, there are endless unanswered questions and endless unposed questions.

You rightfully mention a high correlation with other metrics that make, in my opinion, vitamin d health benefits and health disadvantages scientifically impenetrable.

As a tiny datapoint, I refer to the research of the (on hn at least) highly acclaimed Dr. Rhonda Patrick, who states that 70% of Americans are currently deficient on vitD. She also states that vitD has effects on 5% of gene expression, and is very important in the brain formation of foetuses since it assists the production of serotonin.

If anything, and despite of admittedly huge efforts already, vitD is heavily underresearched and many of its mechanisms unexplored.

We are wasting our time and money looking at Vitamin D again and again and again.

I seriously doubt that because I think exactly what it does is poorly understood. But we do know that people with cystic fibrosis have serious compromised immune function and, among other things, see terrible, deadly lung infections (and account for a large percentage of lung transplants).

Some of the remarks in this discussion have been helpful to me and I've spent nearly two decades -- ever since my diagnosis in May 2001 -- trying to understand my condition.

New information comes out all the time and new tidbits that are reasonably verifiable as true become building blocks for more complex mental models. I am just beginning to understand things I've been squirreling information away about for a lot of years with a keen interest because my life literally depended upon such understanding.

I have kind of "bookmarked" this discussion, in part to get me ready access to the article it covers. I'm short of sleep today and not following things well and this piece is piquing my curiosity in ways that most discussions of vitamin D fail to do.

I think this is an exciting era in which to be alive if you have a mystery illness that they don't really know how to fix. The amount of information available at your fingertips while literally laying in bed, too sick to get up, overwhelms what I could find at a library as a child. It is game changing in ways that most people seem to fail to appreciate.

Just because it doesn't cure one thing, we shouldn't consider it for others? Should we toss our antidepressants because they don't cure respiratory infections?

I believe there's a plausible mechanism in this case, and related studies on respiratory infections where an effect was found. Also, in terms of studies, often the no effect data is from bolus doses, which don't seem to do a good job moving the needle.

> Vitamin D has been endlessly promoted as a treatment for many diseases due to evidence from observational studies, but hundreds of millions of dollars in randomized controlled trials have never demonstrated it to be effective for any disease except rickets.

This randomized controlled trial, with 11000 participants "confirms vitamin D protects against colds and flu":


Although there is no proof that things like vitamin D are a cause of something, I think it might be useful to treat them as biomarkers.

(basically saying they correlate, without leaping onto the cause bandwagon)

When looking at studies that show Vit D is not helpful, it pays to understand whether the dose is significant or not.

In this case, 2,000UI is not a significant amount.

Someone in the UK can generate 10,000UI - 20,000UI from spending 5 mins in the midday summer sun.

This amount various depending on whether they are in the countryside, where about 25% of UVB radiation is absorbed by plants or sunbathing on a concrete/sand surface can reflect 100% of the UVB upwards. If sunbathing in a polluted area, the low level ozone can also reduce the UVB radiation reaching the ground depending on the pollution levels.

The Vit D Receptor has a zinc finger which is seems to only be structural, so it would seem that without enough zinc in the diet, even the 2776 VDR's in the human body according to the Wellcome Trust, Cambridge Aug 2010, most of which are concentrated around the immune system genes wont function optimally.

A point worth noting about Vit D3 supplements derived from Lanolin, aka Sheep Fat/Oil, as most sheep are dipped in organophosphates (Nerve Agents), there is a chance that you could be exposing yourself to harmful residual levels of organophosphates. I've yet to see any legislation which monitors this in Vit D supplements in any region of the world (if you know of any please reply so I can update), so megadosing Vit D3 supplements could be increasing the tiny residual amounts of organophosphates to significant and possibly harmful levels. In a study on different Vit D3 specific supplements, the amounts quoted also varied significantly.

Its also worth noting that due to the way patents work, manufacturers of Vit D serum levels measuring equipment use different methods and markers to calculate your serum 25(O)HD levels, 10 years on, the medical equipment is still not standardised as noted here. https://ods.od.nih.gov/Research/vdsp.aspx In my own limited tests using NHS equipment, the amounts measured varied by 45%.

Like all fat soluble vitamins, D3 (25(O)HD) also has a half life of about 28days so you could do what I have done in the past and purchase some UVB reptile flo tubes and bask under them during the winter months for a few hours a day to monitor serum levels. https://www.reptilecentre.com/blog/2016/09/difference-t8-t5-... If you want to know how UVB levels vary around the world, this is a good resource http://www.uvguide.co.uk/ reptiles like some other mammals also need UVB radiation for good health.

I could go on, I dont agree with some professors in this field, sometimes science seems to be a scientific Ash conformity experiment which can prevent you from becoming a qualified expert and harm your health but as always with health, there is no panacea and a variety of factors influence our health. For example if your kidneys and/or liver are not healthy you wont be able to make as much Vit D. Diet also plays a part, but if you should find yourself getting into hypercalcaemia territory, increase your Vit K intake, eg eat Brussel Sprouts, and increase your Leucine and Lysine intake as these keto amino acids also stimulate all type collagen synthesis and can reduce the calcium in the blood stream.

As the airways are the main entry point, it would seem logical to increase Vit A intake because this is required by all epithilial cells as is choline for cell membrane integrity, and choline also helps to reduce the pressure in alveoli to facilitate gas exchange which also increases physical performance but could make it easier to breath when on a ventilator and Choline also helps clean the blood through methylation. Epithelial cells secrete things, so those two supplements will enable the lungs and airway secretions to work properly producing enough functional mucous in order to trap pathogens before it even gets into the lungs where the real damage can take place. Like I said it would seem logical to do this, but I'm not an expert, just a self taught IT geek like many of you guys. :-)

This should be the top comment.

Guaranteed that not a single study exists where they intentionally exposed people to a live virus (since it's unethical and horrific) so whatever studies you're referring to are completely irrelevant. If not, please link to a relevant study. Depression is not a virus.

A number of influenza challenge studies have been conducted on human subjects.


It is not surprising at all that Covid-19 matches what we already know about Vitamin D and Influenza. There are consequences for radically altering the environment in which humans evolved. We were nude outdoors and now we are clothed and indoors. When we do briefly go outside, we are all conditioned to slather on sunscreen, which blocks all Vitamin D generation.

Why do people tend to get sick in the wintertime and not the summer?


Humans have being wearing clothes for about 170,000 years, indoors and outdoors, long enough for a evolutionary response. Along with fire, clothing is one of our great inventions and allows humans to live in colder climates than we could otherwise. We have, along with other creatures like lice, been evolving since we started wearing clothes.

But why do people get more sick in the winter, when they are forced into close proximity with other people, making illness easier to spread, rather than the summer, when people are outdoors more, and can do things like walk to work in the warm summer sun rather than take the bus in the cold winter rain and snow? Stated differently, we naturally do more social distancing in the summer.

Sure, there has been evolution. Like the adaptation of white skin for humans in northern latitudes. Why was it so important to evolve pale skin for humans living in high latitudes?

Social distancing in summer as a reason why people don't get sick is an interesting theory, any studies that support it?

>Why do people tend to get sick in the wintertime and not the summer?

There are lots of reasons for that. Vitamin-D is just one of those theories. There are also behavioral changes, such as people spending more time indoors and in sealed spaces. There is also the fact that certain viruses may survive better in colder, drier climates. There are also some theories that particles evaporate more quickly in the heat.

Not to mention... humans started wearing closes about 100,000 years ago.

Agree, it is a theory and one I believe. Also how/why white skin evolved is another data point to consider. Lighter skin means more Vitamin D in the summer months which is vital for humans in northern latitudes.

Clothes sure, but still were outside in the sunlight during most of the day without sunblock. Take a look at hunter gather tribes still alive today. Not a whole lot of clothes! But sure, some.

People need to be really careful when sharing papers like these and repeating their conclusions without the appropriate disclaimers. That's always the case, and especially during a time when so many people are unable to consult their doctors and resorting to self-medicating based on hearsay and overconfidence in their own ability to interpret scientific papers.

To be clear, I'm not saying vitamin D deficiency in relation to Covid mortality isn't a valid line of inquiry for the health community to take their research in. But from what I can tell, this is far outside the authors' areas of expertise.

I'd say this kind of thing in particular has the potentially to be even more dangerous than irresponsibly discussing the effects of something like hydroxychloroquine, because so many people don't realize how dangerous vitamins and other such 'natural' remedies can be when taken without the supervision of a medical professional.

Interesting but a there's a decent chance of correlation not causation. Unhealthy people and people over 65 (i.e. those most susceptible to serious COVID complications) are the same group that are most likely to be Vitamin D deficient. The primary source of Vitamin D is sunlight. People over 65 tend to stay indoors, etc. People with darker skin are also more prone to D deficiency due to increased melanin, but also have higher rates of obesity, more likely to suffer from diabetes, are more likely to live in cramped conditions, etc.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447083/ https://www.cantonmercy.org/healthchat/42-percent-of-america... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075634/

There's a lot more data here that specifically tested about vitamin-D levels in early and late stages: http://agingbiotech.info/vitamindcovid19/

I agree that causation hasn't been completely proven, but there's a lot of data to support it could be causative.

From the paper:

> After correction for age, sex and previous illnesses, the risk of death is 10 times higher for people with vitamin D deficiency.

That said, it could still be correlative and not causative with some different underlying health issue.

> That said, it could still be correlative and not causative with some different underlying health issue.

On the other hand, maybe Vitamin D deficiency is the cause or one the causes of those underlying health issues.

This isn't the first set of studies on Vitamin D3 and COVID-19, and very happy more is coming out that is supportive: http://agingbiotech.info/vitamindcovid19/

Per Nicholas Taleb this is "optionality", very low risk and potentially very high reward.

"Pending results of such trials, it would seem uncontroversial to enthusiastically promote efforts to achieve reference nutrient intakes of vitamin D, which range from 400 IU/day in the UK to 600–800 IU/day in the USA. These are predicated on benefits of vitamin D for bone and muscle health, but there is a chance that their implementation might also reduce the impact of COVID-19 in populations where vitamin D deficiency is prevalent; there is nothing to lose from their implementation, and potentially much to gain."


> The rapid increase of vitamin D levels in covid-19 infected patients with vitamin D deficiency (< 30ng/ml), as well as vitamin D supplementation for doctors, nursing staff and risk patients to a healthy blood level of 40-50ng/ml, is - in the authors' view - the only conceivable solution to effectively contain the corona pandemic.

Research paper warning alarm sounding here.

I don't know if this should really be considered a "research paper" even.

This is a pretty poor article on an interesting topic.

> Vitamin D deficiency causes a 10 times higher death rate in Covid-19 patients according to recent studies.

This is a hugely overstated conclusion - and none of the studies presented are able to make causal claims to back this up. This is a load of malarkey.

I've been very frustrated in my attempts to raise this issue with the local health department where I live. I was brushed aside, and was told "correlation does not imply causation". I doubt that the person on the phone wanted to get into a conversation about dynamical systems or nonlinear data analysis, so I didn't even go there.

Instead I sent a letter full of references to published research, and citing other letters (peer reviewed) urging public health officials to recommend safe levels of supplementation. I received 0 engagement. I should really send the letter every day until someone responds.

Aside from all of the promising anecdotal evidence and population studies, there is plenty of established theory to understand just how Vitamin D might help lessen the load of Covid-19. Decades of published, reviewed research have shown that Vitamin D:

- helps regulate calcium metabolism and ionization... disregulated calcium levels are also linked to poor covid outcomes

- downregulates some of the same inflammatory cytokines involved in the positive feedback loops seen in bad covid cases

- directly regulates the expression of ACE-2 genes

- regulates the renin-angiotensin system

- regulates circadian rhythm

Other supplements that work with Vitamin D to help regulate calcium metabolism and ionization are also promising, including K2 and magnesium.


A friend of mine who's a doctor also told me that a lot of people with bad covid outcomes just have general electrolyte imbalances. To what degree is this pandemic just a manifestation of basic malnutrition on a massive scale?

At this point, I've come to the conclusion that there is a systemic conflict of interest in many health systems around the world. It's most blatant in the US. Specifically: It seems that there are certain "neo-Malthusian" individuals high up in the chains of command who simply have no interest in implementing low risk, low cost measures that prevent loss of life, and instead use their power to further cater to the already privileged groups of people they deem fit for life. This goes beyond covid-19.

I'd tend to agree with you. There's a lot of pharmaceutical money to be made on this crisis, especially if Covid-19 becomes seasonal. Don't want to waste that opportunity by treating it with something cheap like Vitamin D.

In line with how Monsanto covered up studies showing the dangers of Roundup (and faked other studies that indicated no danger, and did a fair bit of astroturfing, iirc), I'd expect to see a lot of misinformation in the future about the ineffectiveness - maybe even the danger? - of Vitamin D supplements.

Thank you for posting this. K2 and Mg are important to include in a D3 supplementation plan. You could also just get more sun exposure. Aside from possible COVID benefits, serum D levels correlate well with many other positive outcomes. Doesn’t prove anything, but at some point you have to bow to a preponderance of studies that strongly imply a positive outcome you care strongly about. Especially with low cost and essentially no risk.

Tentative paper in the Lancet about it.

Quite why there is so much objection to something that is likely a good thing in any case makes you wonder what the issue is with it.


Great article!

A simpler explanation is profit motive; it doesn't 'pay' to promote free/low cost alternatives. Most of western medicine is geared this way, imo.

I agree, and don't believe your explanation is all that different from mine. Market driven medicine implicitly favors people who for whatever reason find themselves in the position to pay for care, and slowly but surely culls those who aren't.

People with the power to regulate health care "markets", to shape the incentive structures and make them less overtly biased in favor of wealthy people, sometimes they do this and sometimes they don't. Currently, at least in the US, in the midst of this unfolding crisis, the power balance seems skewed toward the "let's take a violent trek toward 'herd immunity' as soon as possible" decision makers, many of whom are more or less blatantly eugenic.

In this case, the doctors really do know better. Vitamin D deficiency has been linked to just about every disease. That's because it's a marker of frailty, not a direct cause for most of these diseases. In other words, correlation does not imply causation.

It sounds like you have too much confidence in published research and not enough confidence in your local health officials.

> too much confidence in published research and not enough confidence in your local health officials

I can't figure out if you're being sarcastic, or if you really do think that a local politician knows more about medicine than is contained in actual medical research.

He's been talking with "the local health department", not some local politician. I trust health departments a lot more than I trust techies grepping PubMed. Techies don't have the context to understand and filter bogus research. Studies that correlate Vitamin D deficiency with X goes straight to the mental spam filter for experienced people in public health. If Vitamin D deficiency actually caused all this disease we would be living in a golden age of progress on cancer, heart disease, infectious disease, mental health, etc. because Vitamin D deficiency is easy and cheap to treat.

> That's because it's a marker of frailty, not a direct cause for most of these diseases.

Do you actually know that?

> In other words, correlation does not imply causation.

Sorry, but just because correlation does not imply causation doesn't mean that Vitamin D deficiency isn't a cause.

> It seems that there are certain "neo-Malthusian" individuals high up in the chains of command who simply have no interest in implementing low risk, low cost measures that prevent loss of life, and instead use their power to further cater to the already privileged groups of people they deem fit for life.

Especially the push for new expensive drugs like Remdesivir--by people who stand to profit from the sale thereof--over existing safe, effective, and cost effecient treatment protocols like HCQ-Zn-azithromicin[0].

0: https://hcqtrial.com/

This conclusion (10x higher mortality if deficient in Vitamin D) is rather significant. How trustworthy is this source?

Keep in mind that they aren't saying that their data doesn't say that people not given vitamin D supplements were 10x more likely to die. Instead that people coming in with a deficiency already were 10x more likely to die. Imagine if you had two groups. Group A runs for 1 hour a day outside. The group B is confined to their beds in a nursing home.

Group B is going to have a vitamin D deficiency compared to group A. Group A is also much more likely to survive Covid. However, this wouldn't give you any evidence that vitamin D is the cause of better survival rates. You should assume that it might just be an indicator of better health over all unless you can find some way to control for all the other health factors.

And yet it has been long known D supports the immune system. Being technically-right here is not a good survival strategy.

Borsche and Glauner don't seem very trustworthy, but it is no secret that a vitamin D deficiency is correlated with higher mortality. The comorbidities that are associated with Covid-19 mortality are, pretty much, all correlated with vitamin D deficiency. The real question is, if someone is obese, or has diabetes, or has CKD, or is old, what is it that is making them more likely to die of Covid-19? Is it a vitamin D deficiency or some other related issue? and can supplemental vitamin D help?

My guess is that it helps more than hurts to supplement vitamin D if you are deficient or insufficient. I'd also guess that it is no miracle cure like Borsche and Glauner seem to want people to think.

From a technical writing style perspective, the thing going against this paper is the folksy way of writing. It also includes things called weasel words, such as saying very young doctor, versus young doctor, or even just doctor.

The results are compelling, and I suppose it would not hurt to take a prophylaxis of vitamin D (5,000 units per the article?) as compared to a prophylaxis of something else, such as hydroxychloroquine (or Lysol!)

People in my doctor friend's hospital taking HCQ got arrhythmias at a higher rate and often didn't get better. It is not a miracle cure and is quite dangerous in the alleged "treatment ranges".

I am a bit stunned that people are still going on about HCQ after all this time and the many trials. I feel this comment by a virologist is the key to understanding why it got so hyped and is not working:

https://www.sciencedirect.com/science/article/pii/S016635422... (May 2020)


• In vitro data suggest that chloroquine inhibits SARS Cov-2 replication. • In past research, chloroquine has shown in vitro activity against many different viruses, but no benefit in animal models. • Chloroquine has been proposed several times for the treatment of acute viral diseases in humans without success. • The outcomes of some current clinical trials of chloroquine in China have been announced, without access to the data. • Peer review of the results and an independent assessment of the potential benefit for patients are essential."

Based on the downvotes, it appears that I was unclear. It is NOT SAFE to take HCQ as a preventative. (And ingesting Lysol is plain nuts.) It may be okay to take D supplements as a preventative, but based on Deva Boone's advice, that comes with risks over the long haul.


"...an extensive discussion of the differences between the death rates of New York City and Lagos, Nigeria, which both received infected travelers around the same time. NYC's high rate has been linked to population density, poverty, overcrowding, and ethnicity. Lagos is a crowded urban center of about 22 million people with 30 families often in a single building sharing the same bathroom, and none of the factors mentioned favor reduced death rates in Lagos. Lagos further has lower quality of medical care. Yet NYC had a death rate 600 times higher. The younger population can only account for a small part of this difference. Mitchell concludes that there is a crossover prophylactic effect of antimalarial agents against COVID-19."

The paper that is talked about here doesn't make a very strong case for prophylaxis use of hcq. They may look at population-adjusted death rates, but that's not really enough. You could do the same things between different neighborhoods in NYC and probably see huge difference in death rates that may actually be caused by obesity or so many other factors.

I will grant that prophylaxis use of HCQ is much more interesting than its use in treatment, but I don't think this paper is very strong.

As I wrote at https://news.ycombinator.com/item?id=23025501 :

There is an app I've been using to track my Vitamin D for a few years now: http://dminder.ontometrics.com

(Not affiliated with the app, just happy with it.) It tells you the sun angle, peak hour of the day, and maximum time you should be in that day's sun based on your skin type, to avoid getting burnt while still getting enough D.

Be careful though - you might get a little OCD about Vitamin D tracking with this app. I did, and mainly use it now for checking how long it is safe to stay outdoors. (Instead of full blown tracking.)

Is this a peer-reviewed finding? As someone without expertise in the area how do I evaluate its credibility?

It does not appear to have been peer reviewed. It is being hosted by a diet book author, which should be a red flag. The most reputable source they cite for correlating Vitamin D level with Covid-19 cases and deaths called the correlation "crude" [0]. It is a weak correlation. Their suggestion that there have been controlled studies on infected patients seems to be misleading. As far as I can tell from the sources they cited, none of them administered Vitamin D to Covid-19 patients. I think the trials they are citing were performed years ago on pneumonia patients, not on Covid-19 patients [1].

[0]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7202265/pdf/405...

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4939707/pdf/mai...

How do you evaluate the credibility of anything in life? I'm not being facetious, it's a question I've been asking myself a lot lately after making decisions based on the information from a medical doctor, who, turns out, was not competent to make certain affirmations.

I have been asking that too.

What steps should I take to verify information without becoming an expert in the field?

What about more nuanced political topics?

There's other studies cited in this discussion. Those are peer-reviewed and do back up what the post is claiming.

I heard about this just the other day on an episode of the Radiolab podcast, if you're interested in listening to a nice narration to complement the article: https://www.wnycstudios.org/podcasts/radiolab/articles/invis...

My wife just had a Vitamin D test which came at 15ng/mL, so we are chuckling right now that she is 100% going to die if she gets COVID.

Dark humor aside, that is one hell of a chart. Really helps explain the huge drop in death rate over the summer.

I must say it’s a bit of a missed opportunity to build up herd immunity while the sun is shining here in the northern hemisphere.

Supplementing with vitamin D should be easy enough to test. Given that most people get their necessary vitamin D by going outside, couldn’t the presence/lack of this vitamin be an indicator of other lifestyle choices that may affect the person’s ability to fight off the disease?

Sure, but a bigger confounder is probably that vitamin D deficiency is associated with metabolic syndrome, CKD, obesity, diabetes, etc. These may be, for some people, indicative of lifestyle choices as well, but those choices are, I'd guess, not the direct cause of a person's inability to survive the disease.

Everyone should try a Vitamin D cycle if only to see if makes a big difference in daily life, especially if you live in area with sad winters. It's one of the few supplements that dramatically improves mood for those deficient or sensitive to large doses.

I can provide my anecdote. I live near Portland, OR and been taking 5000IU of Vitamin D for years. It doesn't do anything to help with seasonal sadness. Neither do those "sun lamps". The only thing I've found helpful (although short-lived) for that is literally leaving the state for a week to somewhere warmer; like Hawaii or San Diego. The sadness comes back shortly after returning though, and sometimes even worse than before. It seems to me that treating seasonal depression is more complicated than simply taking medication or sitting in front of a lamp.

Yeah, it would be nice to be able to replicate a warmer and sunnier climate indoors during the winter.

Another thing you can try is to use red to near infrared light which has been shown to affect the mitochondrial electron transport chain. I read "Brain Photobiomodulation Therapy: A Narrative Review" a couple of days ago which is pretty interesting.


After having several kitesurfing vacations ruined by sunburns, I decided to just go to a tanning salon in the winter. It had a profound mood effect and respiratory effect almost immediately. Now I go a few times per month in winter regardless if I am going to the tropics. The UV does is completely metered.

It may be a risky, but given that people that work outside have half the risk of melanoma as people who work indoors, I think regular low dose UV exposure may be a net positive even for cancer risk.

Spending 5 minutes under UV lamps is a guaranteed way to get a huge dose reasonably safely, and you will know the effect almost immediately. The vitamin D seems to be maintained for 2-3 weeks after as well.

One concern that I would have is that I've heard that the light from a tanning salon doesn't match the light output by the sun. Supposedly the sun has more UVB or something and there are reasons to believe it may be healthier. Do you, or anyone else, have any knowledge on this?

That is a concern, and the salons pitch expensive machines using high pressure bulbs with basically no UVA which will make your skin brown with little worry about sunburn and has little vitamin d effect. Since you wouldn’t be going for aesthetics, the best is to use one of the cheap beds that makes UVA and don’t go for very long. Your skin will take a month before it gets even subtly darker.

The salons call the cheap machines “sun burning” machines to up sell the more expensive “browning beds”, but just use that cheap machine and only use it for say 5 minutes instead of the max 20.

I also cover my face. I am in no way noticeably tan after years of doing this, and the low dose protocol I use makes my body similar to the color my forearms are from normal sun exposure.

I hope that is helpful, and it was years ago that I was evaluating the risks and I don’t have the exact figures anymore, but you can lookup the UV profile of the bulbs that are in the machine. Just google search the numbers on the bulb.

Vitamin D tests aren't usually too expensive (as far as medical tests go), so it might be worth just getting tested rather than trying to see what difference it is making (which can be tricky if you are someone sensitive to the placebo effect or if the effect of vitamin D supplementation isn't immediate or what not).

If you are trying to use it to treat mild depression specifically, a placebo effect is great! Placebo effects get a bad rap. If something improves your subjective quality of life that should be considered a win, especially for depression.

Honestly the best thing vitamin D has going for it is being super inexpensive and safe. Because of that you can supplement vitamin D for almost any reason and expect to see at worst a very small cost (someone up thread said 3 cents a day, which seems in the ball park) and at best a significant subjective benefit (even if it's from a placebo effect).

Placebo effects can be great; they can mask underlying issues though. Also, if you actually have a vitamin D deficiency (or some other health issue), it could be good to know why. Perhaps your kidneys are having issues, for instance.

Dr. John Campbell has a lot of videos about vitamin D and covid-19 -- here is one from last week https://www.youtube.com/watch?v=cv4iINxf4IM

"average age group of the 20 patients" == 60 years old

Is 20 a high enough sample size for any meaningful conclusion from a study like this?

The Harvard Gazette: Study confirms vitamin D protects against colds and flu


University of Colorado Anschutz Medical Campus: Vitamin D reduces respiratory infections


the problem with vitamin D is there's a lot of confounders that D is a proxy for, particularly met-syn and old age, so until there's actual mechanistic descriptions for how D inhibits covid severity, i'm remaining cautiously-optimistic-bordering-on-skeptical about its curative powers.

Would it be reasonable to hypothesize that, through lack of sun exposure and ensuing vitamin D deficiencies, lockdowns kill more people than they save? (that is, the increase in mortality would more than overcome the decrease in cases)

We cannot know for sure of course, but is it unreasonable to even consider?

My state started locking down early, but at no time were people not allowed to go outside. Closing bars seems unlikely to contribute to vitamin D deficiency, for example.

But strong lockdowns in which you're not allowed to walk outside unless you have a good reason happened in a lot of countries.

I think the findings are good and interesting but I wish we could dodge the politicized angle of this:

"A lockdown would then be just as unnecessary as the justified fear of our elderly fellow citizens and the risk groups, which imposes an abnormal life on all of us."

I've been maintaining a complete-ish repository of vitamin D covid research here:


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