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.

https://www.sciencedirect.com/science/article/pii/S221462371...

——————

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%.

https://pubmed.ncbi.nlm.nih.gov/31531088/

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.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4463890/

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%.

https://pubmed.ncbi.nlm.nih.gov/31531088/

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:

https://youtu.be/v3pK0dccQ38?t=4105

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.

https://www.cdc.gov/nutrition/infantandtoddlernutrition/food...

https://www.healthline.com/nutrition/fortified-milk#3

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.

https://en.wikipedia.org/wiki/COVID-19_pandemic_in_Finland

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:

https://www.consumerreports.org/supplements/how-to-choose-su...

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.

https://originmaine.com/nutrition/jocko-d3-gel-capsules-360c...

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."

https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...

https://www.news-medical.net/health/Vitamin-D-Overdose.aspx

https://www.healthline.com/nutrition/how-much-vitamin-d-is-t...

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)

https://www.healthline.com/nutrition/vitamin-d-from-sun#time...

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

https://news.harvard.edu/gazette/story/2017/02/study-confirm...

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

https://www.sciencedaily.com/releases/2016/11/161116103005.h...

> 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.