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Comment by r1ch | Hacker News Reader

Please do not take 5000mg/day of Vitamin D. The author confuses IU and mg which is very dangerous.

I also noticed that. Opened issue: https://github.com/ncase/blog/issues/4

Hi, author of the blog post here! Yes thank you for catching this awful typo, it's fixed now! I did write "4000 or 5000 IU of Vitamin D" everywhere else in the article -- main text, conclusion -- just my luck that the one place I mess up is right at the very start.

(Do not take 5000 mg, that's 200,000,000 IU. You'd have to chug dozens of bottles per day)

Let’s hope the LLMs haven’t picked it up yet and are suggesting it to everyone already. :)

Hi, I’m curious about medicine in general and I’m considering going back to school.

what formal education do you recommend so that I can better understand this data?

It’s clear you’ve dealt with anxiety before, but this analysis is super thorough!

And thank you for quickly fixing that mistake - that could have really harmed someone.

Colon Blow: "It would take over 30,000 bowls. [ a giant pyramid of cereal bowls shoots up from under the man, who yells in terror as it rises ] To eat that much oat bran, you’d have to eat ten bowls a day, every day for eight and a half years."

https://snltranscripts.jt.org/89/89ecolonblow.phtml

That would be 5g. At this point everyone should notice that something is off. :-D 5000 mg of vitamin D3 = 200,000,000 IU (200 million IU)

More often written as 200,000 IU as 5000mg of D3 is not written as 5,000,000mcg

The author simply (and terrible mistaking) typed [mg] instead of [UI] in the first paragraph: if readed entirely, the author correct this typo in every other sentence

Still it needs proof reading and definitely a BIG WARNING that anyone who reads the article should first talk with their doctor before trying any "recommendations". Some of these "recommendations" could literally kill someone.

I bought the once weekly 50,000IU bottle on Amazon and am currently taking 4 a day and I am ignoring all growing signs of vitamin D toxicity because I read this guys blog and never once ever decided to consult another source, including later paragraphs in that same blog because there was no warning. Without a warning, you should blindly follow all medical advice you read online.

That is that pathway to death you are worried about?

I was going to say, wouldn't following through on this mistake require you to not just spend a ton of money on pills but also take tons of them a day? I'd like to think this would give even the dumbest of people pause just because of the practicality aspect.

You might be surprised. Medical journals that specialize in reporting one-off cases have some wild articles.

Why didn't the author notice? AI slop?

doctors prescribe vitamins in MG, but they're sold in IU. It's an easy mistake to make.

People don't always realize: https://www.chemistryworld.com/news/university-fined-in-caff...

Wow that must be hell

And must have tasted like highly concentrated rat piss. XD

Even taking more than a knife point renders a complete can undrinkable. Not to speak of 30 fucking grams.

I also had to immediately think of this case.

If you don't have an underlying condition it is way better to get the Vitamin D from the sun in 10-30min increments per day after which you are saturated for the day. Overdose is not possible via the sun (excluding sun burns of course).

> A single, optimal sun exposure session might produce the equivalent of 10,000 to 25,000 IU from a supplement, but it will not keep increasing with more time in the sun. That's your max per session.

From NHS Scotland:

"In Scotland, we only get enough of the right kind of sunlight for our bodies to make vitamin D between April and September, mostly between 11am and 3pm."

https://www.nhsinform.scot/healthy-living/food-and-nutrition...

Personally I found that taking Vitamin D supplements made quite a bit of difference - and I spend a fair amount of time outside (~3 hours each day).

And in Norway we often don't see the sun during certain months, due to it only being up for a few hours in the middle of the day (when we're working). And even if I was outside I would be covered in clothes.

We have a saying here to take cod liver oil all months ending with R (in Norwegian that's September to Februar) to get both omega 3 and the vitamin D.

Indeed, I was going to add that Scotland isn't really that far North (or indeed South) so there will be lots of places where the problem is far worse!

.. how do you calibrate this against a cloudy sky? It's pretty dark up here at 56 degrees north, and on top of that it's been overcast for days.

It also sucks a lot when it's dark before starting work, dark after leaving work, and during the day rather cold to be exposing skin to the sun.

Agreed, but I live in Sweden so I take vitamin D supplements every winter.

During the spring, summer, fall months I barely need it since I'm outside so much with my dog.

This is nonsense advice for pretty much anybody that is shovelling snow right now.

Why don't you just travel to the south during winter? /s

Check local/national advice. In many places it is officially advised to take vitamin D supplements, especially in winter or if you have a darker skin tone.

Your suggestion sounds a bit detached from reality of many people.

In many countries it is physically impossible to get enough vitamin D from the sun, even if you go out naked.

Also did you ever notice that the cheap apartments in many places are facing north and do not have a balcony, and of course do not have a private garden? Now you are reduced to going to a park which in the "cheap" areas is also not a good spot to chill for 30 minutes.

In winter, even on a sunny day, only tiny fraction of your skin is exposed to sun. 10-30 min of sun when you are wearing tshirt and shorts is much different from 10-30 min of sun when you are wearing long sleeves, gloves, and a scarf.

It's not really the exposed skin that's the issue. At higher latitudes the ultraviolet (UVB) gets scattered by the longer path through the atmosphere and so even if you were naked you still wouldn't be getting enough.

> it is way better to get the Vitamin D from the sun in 10-30min increments per day

spoken like someone who has never lived in the UK

Next time I get sunburn I'm calling it a vitamin D overdose

I would argue to do both in the winter, since sunlight has other benefits than just Vitamin D synthesis, like mitochondrial health and better circadian signaling for better sleep quality.

Don’t guess; just get your vitamin D levels tested. It’s $20, you can just buy it à la carte.

For some people even in sunny areas, 5000 IU might be needed to get you in-range. This is highly individual.

Yeaaah, in Finland the sun just fucks off for multiple months over the winter.

It's much cheaper to take a few pills than it is to travel 3000km south to see the sun for 30 minutes :D

We even put Vitamin D in milk by default just so that people would get some extra.

Isn't the oral intake pretty much negligible anyway? I remember getting a vitamin d supplement in a syringe (to be put on bread, from a physician) containing a very large dosis.

I'm not stating the dosage is wrong. Looks like it is anyway.

It is easily possible to overdose on oral Vitamin D tablets and damage your body.

Source? There have been many articles on HN showing the RDA to be ~10x too low (something like 5,000 IU) and that the daily safety limit to be significantly higher than that (something like 30,000 IU).

Edit: for clarity I am not saying it is impossible to overdose on oral tablets, but rather that with most tablets 400 IU to 1000 IU and the safe limit so much higher than these, it seems like it would be extremely unlikely for someone to be taking 30+ tablets daily. Not impossible, but not easy either.

That's a bit of a non-sequitur, isn't it? The debated point is how oral intake as a delivery method can pan out specifically (and its limits), not the dosage limits of Vitamin D in general. Think consuming a drug vs injecting it.

> Source? There have been many articles on HN showing the RDA to be ~10x too low (something like 5,000 IU) and that the daily safety limit to be significantly higher than that (something like 30,000 IU).

First: the RDA and the safety limit are not the same, and an RDA in a country being too low does not mean that the maximum safe dose is wrong.

And it certainly does not mean that there is a higher risk in under-dosing than overdosing when taking the RDA (which already includes recommendations for supplementing if you spend most of your time indoors).

I'm not a scientist, so I only know what physicians told me and what's explained in news publications or by consumer advocacy non-profits.

Here are a study (which I didn't read) and the NHS's advise on Vitamin D toxicity:

https://www.ncbi.nlm.nih.gov/books/NBK557876/

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

The study says:

> Most cases of vitamin D toxicity resolve without serious complications or sequelae. However, in some instances, severe hypercalcemia can lead to acute renal failure requiring hemodialysis. Cases of permanent renal damage due to vitamin D toxicity are rare.

Which sounds good, but I don't think it supports that there is no risk of oral Vitamin D overdose.

The first link makes the problem sound like it can happen to anyone, but then when you tease out the details;

* Toxicity resulting from lack of monitoring is frequently seen in patients requiring high doses to treat ailments like osteoporosis, renal osteodystrophy, psoriasis, gastric bypass surgery, celiac, or inflammatory bowel disease.

* Patients who are on high doses of Vitamin D and taking inadvertently increased amounts of highly fortified milk are also at increased risk for vitamin D toxicity.

* According to the latest report from America's Poison Centers (APC), there were 11,718 cases of vitamin D exposure recorded in the National Poison Data System. More than half of these cases were in children younger than 5 years.

* The clinical signs and symptoms of vitamin D toxicity manifest from hypercalcemia's effects.

* Clinical management of vitamin D toxicity is mainly supportive and focuses on lowering calcium levels.

* Isotonic saline should be used to correct dehydration and increase renal calcium clearance.

A lot of those point to people drinking too much milk! (enriched milk)

* People with osteoporosis thinking "I better drink more milk for strong bones" when they are already on supplements/medicine.

* Kids drinking lots of milk and presumably not drinking any water - hence the dehydration.

PS: There are a lot of people out there that don't drink any water, and stick to juice or milk or soda, etc. They are not always fat, but that doesn't mean they don't have issues.

I've read the article by now and I like it. It's balanced, more so than the comment section made me think.

And my takeaway is not that everyone should be taking 10k IE, but it's a great reminder to be more consistent in taking my Vitamin capsules in winter.

I'm still standing by my point that it's "easy" to overdose on Vitamin D. Like the article already mentions, one should remember possible kidney issues and not take insane doses of it.

What the recommended daily intake should be, I don't know.

The whole reason I'm commenting on this is I used to take one of the "top" antidepressants on this list.

And I am a skeptic of antidepressants, that doesn't mean I deny all positive effects in people who are prescribed them, of course.

For what it's worth, it's also easy to overdose on Venlafaxine. It's still considered safe.

Just an example to make clear that my comment was not a critique of taking Vitamin D in general.

I don't find the article's main point surprising though. That's the reason I'm taking Vitamin D, too. Doesn't mean that it's impossible to overdose, and this point is also important, because many people still think that it would be impossible to take too much of an vitamin or mineral. Thankfully, high-dose Vitamin A / retinol supplements are not as widespread.

Why would you not be able to overdose orally? It's not like it stops absorbing past a certain dose, and there is such a thing as too much (especially if vitamin k2 is lacking)

I do know somebody taking way more than 30k/day though.

Seems to be a thing in conspiracy theories "they try to hide those simple tricks from you (drinking bleach, ivamectin, 100k D3, ...)

It may not be that crazy in fact, unless it's prolonged. Don't take 30k/day for several months without supervision, but doing that for a single month is unlikely to harm you if you start from deficiency. Some people may need even more than that.

In any case, keep your blood levels in check. It's cheap and easy. There are even services you can order to have your blood sample taken at your home.

Here is a case study and discussion from a parathyroid surgeon:

https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-st...

"There are people out there doing just fine on 5000 units of Vitamin D daily. I only see the ones who develop high calcium levels. But I see enough of them to know that this is not an exceptionally rare occurrence. I have been to lectures in which physicians have claimed that Vitamin D toxicity almost never occurs. In my experience, this is false. I have seen many cases of Vitamin D toxicity in people who were taking the recommended dose from an over-the-counter bottle.

Unfortunately, none of those patients were warned about the potential for Vitamin D to cause high calcium. They all believed that they were taking a supplement to improve health and that there was very little risk. Supplements don’t require prescriptions, and most do not have the warning labels that accompany medications. For Vitamin D, a steroid hormone, that may need to change."

I would say it's almost impossible with typical packaging. What makes it easy?

Oral has felt very effective for me. I take a daily supplement that has roughly 100% of the recommended daily dose of everything. I split it in half.

For D3, it is 25mcg / 1000 IU / 125%

After splitting in half it's 12.5 mcg / 500 IU / 62.5%.

I take with some fat-containing food to allow ir to absorb which is usually breakfast (yogurt, some nuts, some kind of fruit, oats), and it's a night and day difference in my mood (how easily I can control my temper if already agitated, how easily I brush off annoying stuff, takes the intensity off of my reactions and mood during conversations).

I did a blood test before starting, and if normal is between 30 - 70, I was at 10. Dr prescribed megadose of D2, followed by daily D3, but I skipped on the megadose and went straight to D3 -- makes me wonder if a megadose would build up my stores since D is fat-soluble and make it so I could miss a day and not notice.

All of the above is anecdotal from me, a self-professed cave dweller, but it's been a couple of years now, and I still notice the difference. Also, what I heard from people in Boston is that 90% of them are on a vitamin D supplement. My friend from there laughed at me when I was raving about it, saying "yeah, literally everyone here is on it".

Follow up to this: I did my latest blood test after a couple of years and I'm now hovering at exactly 30. I should probably take that other half.. but my Cobalamin is at the high end so may swap to pure vitamin D instead

That’s a large enough error that it calls the rest of the writing into question, in my opinion.

Also, be careful taking 5000 IU/day of Vitamin D. I did this for a few months and it was enough to send my blood levels over the top of the range, even in winter.

Too much Vitamin D is not good for you. The supplement fans have gone too far in recommending too high of dosages. My doctor said she’s seeing a lot of people with excessively high Vitamin D levels now that it has become popular.

It's usually pretty hard to get to toxic levels though, most people that don't live in a particularly sunny climate won't get anywhere near there on 5000 IU/day.

Just test your blood levels before you start and then after 3 months or so. It's quick and cheap, and the only way to know whether the dose is right.

> It's pretty hard to get to toxic levels though, most people that don't live in a particularly sunny climate won't get anywhere near there on 5000 IU/day.

No, that’s literally what I was doing when I reached the excessive range: 5000 IU/day in winter with an indoor job.

This commonly repeated idea that everyone is deficient and you can’t overdose on 5000 IU/day is wrong.

> Just test your blood levels before you start and then after 3 months or so. It's quick and cheap, and the only way to know whether the dose is right.

Literally what I did.

Every time I explain this online it seems like the supplement people ignore what I wrote and just parrot the same “5000 IU/day and everyone is so deficient you can’t overdose” myth.

> No, that’s literally what I was doing when I reached the excessive range:

That doesn't make it easy for most people. In my case it was barely enough to move the needle, but that's not how it will be for most people either.

> you can’t overdose on 5000 IU/day is wrong

Of course you can (though it would usually have to be really prolonged to actually cause you troubles, and even then it's mostly due to calcium rather than vit D itself). The vast majority of people won't, but you don't know whether you're in that group or not until you test yourself.

> Literally what I did.

That's good, but my post obviously used plural "you" as a general advice.

(BTW. There's no evidence of toxicity below blood level of 150 ng/ml, but there are many guidelines that consider levels way below that, such as 50 ng/ml, as "too high" already)

It can also be at non-toxic levels but still cause arterial calcification.

Even 5000IU a day is huge and will likely result in calcium buildup.

So 5000 IU is the recommended amount?

5000 IU is very high, might be beneficial during the winter for folks with very fair skin. but most probably shouldn't take that much every day

That's equivalent to about 10 minutes of sun exposure. Not very much when you look at it that way.

That comparison doesn't work. Only 10-20% of the vitamin D we intake is delivered through food and the body cannot process more sourcing from food. Even if you take more you will not benefit in an unlimited way, processing more. The skin is much better at generating/making/doing it.

The skin is definitely much better, but a higher than "recommended" dose is definitely (anecdata) effective at bringing up and maintaining the measureable Vitamin D3 level in your blood if you are under the recommended range. It's an important metric to track in your regular blood tests.

I think you mean for those with very dark skin, not fair?

You mean very dark skin?

It's my understanding that northern Europeans evolved fair skin in order to cope with the lack of vitamin D in their diet.

yes, i had it backwards - thanks for the correction.

You got it backwards, it would be more beneficial in areas with few hours of sun for darker skin folks, since they do not absorb as much Vitamin D as fair skin folk do.

absorb or create?

i understand it as: absorbing is in the intestine, generating D happens in the skin when exposed to the sun

Correct, what I meant was absorbing UV light, that then as you state creates D.

According to what I read in a newspaper article, the recommended dose is much lower, at 800.

According to the internet, it is way higher, probably over 9000.

Edit because the comment might be to shallow for HN: I sympathize with the struggle against depression and, after first-hand experience, share the skepticism against the widespread prescription of antidepressants and the methods of evidence presented for it.

Very serious and important topic.

Regarding Vitamin D, I am also supplementing in the Winter, but I have not read the article, which says it has an estimated reading time > 10min. I use one 1000IE (0.025mg according to the package) tablet a day max.

I'll bookmark this discussion page to read TFA later maybe.

It’s important to take Vitamin D, as a fat soluble vitamin, with dietary fat during a meal. Something about bile production and absorption.

Also important to take it with Vitamin K.

Yes, I remember that and have Vitamin D+K combo tablets with calcium.

Seems like it would be best to increase time spent outdoors though.

There's likely significant individual variation in bioavailability. I would start with 2-5K/day, then measure and iterate.

I was taking 2x2000 IU with almost no sun exposure and then did bloodwork. My level was 77.8 ng/mL. The lab's reference ranges listed 30-50 ng/mL as optimal, 50-100 as high, over 100 as potentially toxic, and over 200 as toxic.

I don't know why this is downvoted, I had a very similar experience a while back. I took 4000 IU/day for about 4 months, insignificant sun exposure and ended up at 60 ng/mL (lab listed normal range as 30-40).

My starting levels were unknown but I assumed they were low given my usual sun exposure and some low-energy symptoms (which resolved a couple of weeks after I started taking it). I discontinued VitD then and now I only take 1000 IU/day in the winter.

It depends. I have MS and I take 10k IU. My cousin who also has MS takes 20k but gets regular blood tests for it.

This was linked on here a couple of months ago: [The Big Vitamin D Mistake [2017]](https://pmc.ncbi.nlm.nih.gov/articles/PMC5541280/)

> A statistical error in the estimation of the recommended dietary allowance (RDA) for vitamin D was recently discovered; in a correct analysis of the data used by the Institute of Medicine, it was found that 8895 IU/d was needed for 97.5% of individuals to achieve values ≥50 nmol/L. Another study confirmed that 6201 IU/d was needed to achieve 75 nmol/L and 9122 IU/d was needed to reach 100 nmol/L.

> This could lead to a recommendation of 1000 IU for children <1 year on enriched formula and 1500 IU for breastfed children older than 6 months, 3000 IU for children >1 year of age, and around 8000 IU for young adults and thereafter. Actions are urgently needed to protect the global population from vitamin D deficiency.

> ...

> Since 10 000 IU/d is needed to achieve 100 nmol/L [9], except for individuals with vitamin D hypersensitivity, and since there is no evidence of adverse effects associated with serum 25(OH)D levels <140 nmol/L, leaving a considerable margin of safety for efforts to raise the population-wide concentration to around 100 nmol/L, the doses we propose could be used to reach the level of 75 nmol/L or preferably 100 nmol/L.

Multiple previous discussions:

https://hn.algolia.com/?q=vitamin+d+mistake

Vitamin D is a favorite topic around here:

https://hn.algolia.com/?q=vitamin+d

With K3! Otherwise you're fucking yourself up.

Oh dear, here we go again.

IU, not mg.

K2, not K3.

yes, once i saw that i stopped reading. if the author can't get that right i am not going to trust anything else they say.

Is "IU" another case of xkcd 927?

No, it's to make it easier to dose different kind of biologically active substances. They can have significantly different "recommended weight to eat of this per day", IUs make that sort-of comparable and easier to remember.

https://en.wikipedia.org/wiki/International_unit

The usability issue with IUs is that people are used to scales measuring weight and containers measuring volume, but an IU is different for each substance.

Another issue is insulin syringes are labeled in "insulin units," which hapless folks reasonably assume can be abbreviated "IU."

If you are measuring out a certain number of IUs, and your calculator or formula hasn't asked you which substance you're working with, you're gonna have a bad time.

I used an LLM to summarize and it told me 5000 IU.

Wow, so what value is there in LLM slop exctracted from already dubious self-medication advice?

They're saying that it successfully filtered out the bit where the author told people to overdose by 40000x. I guess that's the value.

There would be value if it pointed out the mistake instead of hallucinating a correction.

GPT5.2 does catch it and warns to not trust anything else in the post, saying no competent person would confuse these units.

I wonder if even the simplest LLM would make this particular mistake.

IU was correctly used everywhere else in the article except that one place with the mistak, so the LLM didn't hallucinate a correction, it correctly summarized what the bulk of the article actually said.

Only recently again I read in the newspaper, that most products are overdosed. There is a typical number that the vitamin D products usually show, and in the article it said, that only up to 800 IU is safe, and everything above is an overdose. There are many products out there with 2000 UI or maybe even more. Beware.

EDIT: Wow, the HN-local doctors at it again. Imagine getting downvoted for sharing information from newspaper article (and honestly labeling that info as such), that probably was written by someone consulting medical professionals. But hey HN will know better!

Misinformation. Do more research.

If you have useful information to share, please do so. Telling people "Do more research" adds nothing to the conversation.

Neither does "I read in the newspaper, that most products are overdosed" to the honest.

Examine.com's page on Vitamin D has a table on tolerable upper levels segmented by age ranges.

https://examine.com/supplements/vitamin-d/

While (I think) I agree with you on the facts here, I don't think this type of dismissive comments are that useful either.

Can you give the replyee some pointers, for example? Link to articles or studies that show a different view?

Just Google it. There's tons of research on this so I don't know why I need to provide a specific link when this is common knowledge.

But also here is something to think about: your body will produce more D3 than that by being in the sun for just several minutes. So if you consider such a low dose of D3 an overdose then you better steer clear of the sun!

The problem with "Just Google it" that you can find a lot of bullshit on this.

You can find scientific papers on Google if you know how to use it.

I do, but surprisingly a lot of people do not.

You can find scientific papers on a lot of search engines, not only Google.

The problem with that is, that you still need to know how to interpret any results and statements within the supposedly scientific papers. If you are not a statistician, you might overlook methodology mistakes. If you are not an expert in the matter of the paper, you might not realize some side condition, that makes some statement or result of the paper irrelevant for your individual situation.

Another overly verbose worthless comment from you. Why do you continue spewing text like this as if you're actually helping anybody?

> But also here is something to think about: your body will produce more D3 than that by being in the sun for just several minutes. So if you consider such a low dose of D3 an overdose then you better steer clear of the sun!

This is another superficial statement, that displays shallow-at-best understanding. Staying in the sun and producing via the skin, and intake via food are 2 separate pathways. You cannot just make wild assumptions about one of those pathways from stuff you know about the other pathway.

And actually: Yes, you shouldn't stay in the sun for too long without proper protection. Having the sun shine on your skin is not some inherently healthy thing. It too comes with acceptable dosage and overdose. Symptoms of overdose are commonly known as getting a sunburn.

Thanks for clearing that up for me.

Hi, Mr. wolf language.

Being at the beach (in summer) for a half an hour will produce 10,000 and 25,000 IU for the average european.

See: Vitamin D and health: evolution, biologic functions, and recommended dietary intakes for vitamin D (293 citations)

So? What's your claim here? Are you claiming that our skin works the same way as our digestive system? That would be a ridiculous claim. And fyi, many people get a proper sunburn, if they stayed in the sun for 30 min straight without protection, at least in summer. So your 30 min statistic doesn't really tell us anything about something being healthy or not.

I've given you everything you need to find out for yourself. Your incredulity on this is a self-confession.

What you have given is rather a comparison, that doesn't stand up even the slightest scrutiny, and an improper citation. I am not gonna read a whole paper on a whim. Cite properly, with proper hyperlink, and at least a page number, and I will consider looking at it.

Could you cite that claim from the paper?

Not OP, but the paper says on page 8

> An adult in a bathing suit exposed to 1 minimal erythemal dose of ultraviolet radiation (a slight pinkness to the skin 24 h after exposure) was found to be equivalent to ingesting between 10,000 and 25,000 IU of vitamin D (Fig. 6).

Doesn't say 30 minutes, but it may be 30 minutes depending on your skin colour and the local strength of the sun.

I think the OP's interpretation of this is wrong. Just because someone was found to have an equivalent of ingesting so and so much, after UV radiation, doesn't automatically imply that it a good idea to ingest any amount of vitamin D. Ingestion is different from exposing skin to UV/sun. The paper probably doesn't state, that ingesting that much will make a person absorb that much from that ingestion, nor does it state, that ingesting some equivalent amount will be safe and without side-effects.

So the paper may be well researched or whatever, but the interpretation of it is questionable.

I can't make any assesment on the quality of the paper as that is far outside my expertise, but as far as I can tell from a quick skim it does indeed make the claim that recommendations for supplements should be significantly increased.

From the abstract:

> The safe upper limit for children can easily be increased to 2,000 IU of vitamin D/day, and for adults, up to 10,000 IU of vitamin D/day has been shown to be safe. The goal of this chapter is to give a broad perspective about vitamin D and to introduce the reader to the vitamin D deficiency pandemic and its insidious consequences on health that will be reviewed in more detail in the ensuing chapters

The full article is available on researchgate[1]. Direct link to PDF [2].

[1] https://www.researchgate.net/publication/226676251_Vitamin_D...

[2] https://www.researchgate.net/profile/Michael-Holick/publicat...

EDIT: I just looked up the author, Michael F. Holick. Apparently he is one the people who identified calcitriol in 1971. I know appeal to authority doesn't prove anything, but it might be prudent to at least consider his findings.

Before I take medical advice from a newspaper, I might as well ask my local esoteric nut.

Can you provide a link to the newspaper article at least while whining about the downvotes?

I would like to, but I cannot, since it is a region-local newspaper that comes as actual paper, that only has a paid online offer, to which I have no access, nor could I post a link to that. If I went through recent paper form newspaper, I could get a photo of the text in German, but then I would (A) need to spend that time, and (B) need a place to upload pictures, without having to make an account, and only then get back to you with a link. To be honest, I am too lazy to do that, just to justify a comment on HN.

That's not unreasonable, but then you also didn't really "cite" your source. Even without photographing the paper, giving the name of it, article title, or author would go a long way.

I think the downvotes are harsh btw and in general HNers have gotten too reflexively downvoting IMHO.

Understandable, but you wrote all of that and you still haven't even named the newspaper.

perhaps citing a source would be helpful

It's unbelievable crazy what the author suggests, even say "10,000 IU if you're feeling daring / have darker skin / live in less sunny climates.".

Just a simple look at the side effects of high dosages:

Safety and side effects

Taken in typical doses, vitamin D is thought to be mainly safe.

But taking too much vitamin D in the form of supplements can be harmful and even deadly. Taking more than 4,000 IU a day of vitamin D might cause:

    Upset stomach and vomiting.
    Weight loss and not wanting to eat.
    Muscle weakness.
    Not being able to think clearly or quickly.
    Heart rhythm issues.
    Kidney stones and kidney damage.

https://www.mayoclinic.org/drugs-supplements-vitamin-d/art-2...

To my understanding Vitamin D is regularly underdosed. Several points:

1) There are lots of studies that correlate Vitamin D production with sunlight exposure. For example, https://pubmed.ncbi.nlm.nih.gov/20398766/ this one lands on 1/4 of a MED = 1000 IU. Of course now we have a MED definition problem, but we're roughly talking single digit numbers for a white person in midday sun in NYC to reach 1/4 of a MED.

2) If you also supplement with Magnesium, a lot of your side effects go away. Vitamin D3 depletes Magnesium absorption.

FWIW just anecdotally I took 160,000 IU per day for a few months along with 800mcg to 2mg of K2 MK-7 and about double the suggested amount of magnesium citrate. I slowly titrated up to that amount over a few months. I am not suggesting anyone else do that as I had a specific purpose slow action TPA when combined with many protease so to speak but just my own experience I did not have any of those issues. I don't know how they came up with them so I figure they are just guessing like they did with the toxic level of selenium which has a funny back story. I am back down to 5000 IU a day. Years later still none of those issues. But that is just me.

I did have one issue related to magnesium however. If I did a very high dose of magnesium taurate and a couple of other chelated forms I would have trouble catching my breath after physical exertion similar to chronic high doses of iodine. Not the end of the world but it was unnerving.

Don't anyone else do what I do. I experiment on myself more than scientists experiment on mice minus the whole dissection bit. I am just continuing some experiments from the 1900's but as I understand it AI will be learning all of those soon. Fascinating stuff really.

I respond well to magnesium oxide and magnesium citrate in capsules but the chelated magnesium gives me heart palpitations or makes them more frequent if I am already having them. I hadn't noticed shortness of breath since the palpitations would have outweighed that.

Hi, I'm the author of the main blog post. Just wanted to say that's a fascinating experience, 160,000 IU a day! I mean, I'm not going to try that, but that's good to hear that 5,000 IU/day for years has been working fine for you. Thanks for sharing!

Hi, author of the blog post here! Thanks for your concern. I do still stand by my claim, since more recent peer-reviewed studies have shown that up-to-10,000 IU is safe. As written in the post:

> McCullough et al 2019 gave over thousands of patients 5,000 to 10,000 IU/day, for seven years, and there were zero cases of serious side effects. This is in line with Billington et al 2020, a 3-year-long double-blinded randomized controlled trial, where they found "the safety profile of vitamin D supplementation is similar for doses of 400, 4000, and 10,000 IU/day." (though "mild hypercalcemia" increased from 3% to 9%. IMHO, that's a small cost for reducing the risk of major depression & suicide.)

So why then does Mayoclinic, etc, all say 4000 IU is the limit? I think because policy is decades behind science (this happened with trans fats), and also policymakers are much more risk-averse. (this is why in California, thanks to Prop 65, up until ~2018, there used to be a warning in every coffeehouse that coffee causes cancer.)

But thanks to your comment, I will edit the intro to note what the official max safe dose is, and that more recent peer-reviewed research shows it's too low!

I've been taking 20,000iu of Vit D daily for years, split into 10k AM/PM

Regularly have my Vit D levels checked and they are always within the upper bounds of healthy reference range

It depends on the person, as a sample size of one I was on 5,000IU and my levels were still on the low end (almost still deficient), and my calcium levels were still safely on the low side as well. Ultimately people should be getting their levels checked before and after to see exactly what the effect on them is

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