How Much Vitamin D Is Too Much? A Case Report and Review of the Literature | Hacker News Reader

How Much Vitamin D Is Too Much? A Case Report and Review of the Literature

pubmed.ncbi.nlm.nih.gov

199 pointsvoisin147 comments

The title doesn’t match the abstract. This isn’t a study of the tolerable upper limit of Vitamin D intake. It’s a case report of a single individual who was taking astronomical doses of Vitamin D with disastrous consequences.

It’s certainly possible to take too much vitamin D without coming anywhere near the silly doses this person was consuming.

Anyone taking aggressive vitamin D doses should invest in a vitamin D test after 6-12 months. If you find your serum results approaching the upper end of the reference range, reduce intake slightly. There are no known benefits to excessive vitamin D serum levels, but there are documented health downsides.

If you find yourself reading pop-science articles with unbridled enthusiasm for megadosing vitamins, you’re probably not reading scientifically accurate health advice. Supplementing with moderate doses is fine, but megadosing anything is almost always flimsy pseudoscience.

Everything you say is subjective (at best) or tautological (at worst) until you put a number to what you are calling a "megadose" or "excessive." "Megadose" is relative and needs to be couched with the emerging (not really, it's a decade old at least I believe) that the current official RDA of vit D is about 4-5x TOO LOW and was based on bad data (or a misinterpretation of the data).

...the current official RDA of vit D is about 4-5x TOO LOW...

The person in the study was taking 162.5x the largest recommended daily allowance.

Fortunately, there is a link at the top of the page, which leads to the very article that OP is talking about.

Whether or not that's true, the article isn't talking about 4-5x the RDA.

It's talking about massive doses beyond even the most aggressive supplementation, much less a normal days intake.

According to the paper she was indeed taking 325 times the recommended daily dose of Vitamin D for 20 months.

The paper is indeed pretty silly. "How much is too much? Somewhere between 1x and 325x RDA apparently."

Thank you for posting the actual number instead of just saying "excessive" or "megadose".

(It's true, I didn't read the article.)

> Everything you say is subjective (at best) or tautological (at worst) until you put a number to what you are calling a "megadose" or "excessive."

The Vitamin D blood level range is clearly indicated on the blood test results. That’s why I suggested that people get the blood test.

Blood test shows too little Vitamin D? Supplement more. Blood test shows you’re approaching or exceeding the upper limit? Supplement less.

There’s nothing subjective about it.

> the current official RDA of vit D is about 4-5x TOO LOW and was based on bad data (or a misinterpretation of the data).

This claim, however, is unbounded. We can’t just go around telling people “more is better” and that the official recommendations are vaguely “too low” and expect people to just guess at the real range.

> This claim, however, is unbounded. We can’t just go around telling people “more is better” and that the official recommendations are vaguely “too low” and expect people to just guess at the real range.

I don't understand this sentence at all. 4-5x is an extremely specific amount, with no guessing.

Megadosing B12 (if your diet isn't already sufficient in it, which is common amongst certain vegan diets) is still a good idea, no? I recognize this might be the only exception.

The trouble with Vitamin D is afaik, as with some other vitamins, that it is fat-soluble rather than water-soluble. So the excess of the Vitamin won't be flushed out through the urine - but rather accumulates in the fat. At some point this accumulation may lead to toxicity ("Hypervitaminosis D" [1]).

Personally, I dose 4000-5000 IU D3+K2 in the darker seasons and that has been working well for me.

Vitamin B12 is water-soluble and therefore should not cause accumulation in healthy people.

[1] https://en.m.wikipedia.org/wiki/Vitamin_D_toxicity

Do you dose the D3/K2 combo on a daily basis? I've got https://amzn.com/B075R56QCQ which i do ~3 times a week.

I did that every day and started to have muscle pains and weakness after a while. After doing some research and experimentations, turns out you also need to take magnesium if that happens.

I can say, as an anecdote of one, that I have been taking 5000 IU of D3 along with K2 and Magnesium every day (almost) for about 3-4 years, with no ill effects and what I believe to be a positive effect, in that I have not been ill at all during that time. Cold, flu, anything.

My beginning D3 levels were 39 ng/ml, so just under the ideal range of 40-60, and not really deficient. I have not tested recently, though I believe my numbers would be higher now. I also try to get at least 30 minutes of sun exposure over most of my body 3-4 times per week. Fortunately I live where I can get good sun exposure year-round. Point is, test your serum D3 level and do whatever you need to get into the desired range, and don't take more than that level of supplementation. I do believe that sun exposure is a better choice than supplements, if practicable.

That sounds like too much, which can cause calcium deposition in soft tissues. I'm 250 lbs / 113 kg and only take 125 μg (mcg) of D3 and 100 of K2 MK-7 once every other day (qod) because of D status for COVID prophylaxis and chronic premature distal osteoarthritis.

Calcium, magnesium, sodium, and potassium in balanced amounts along with K and D maximize bone health. Alkali metals supplementation alone is rarely a good idea because of the often common transports and osmotic competitions.

In general, a multivitamin, b complex, and omega 3 in the form of canned fresh sardines or anchovies (fish oil capsules are typically low in actual 3 and high in 6) is probably enough for most people.

5-10 mg/day of extra zinc during the annual cold season is fine too.

Don't supplement with E without a specific medical need.

Every day year-round or just in winter at high latitudes?

It's my understanding that oral availability is lower than IM, and that people who are deficient get 70,000 IU injections.

I'm entirely untrained, but my amateur evaluation of the situation leads me to take 50,000 IU orally once each week or two. I imagine that twice that amount would be fine, too.

> I imagine...

That's not really science.

Given it's your body, the most valuable thing you have, perhaps a more fact-based approach is warranted?

I was pretty deficient (14 ng/ML) and I was prescribed 50k/week orally.

You are spot on: https://en.wikipedia.org/wiki/Hypervitaminosis

I don't see any evidence that it's a bad idea, but from poking around I get the feeling that there is still a lot about it that we don't know.

For instance, it may be monkeying around with blood flow to the kidneys somehow.

"Among patients with diabetic nephropathy, high doses of B vitamins compared with placebo resulted in a greater decrease in GFR and an increase in vascular events."

https://jamanetwork.com/journals/jama/fullarticle/185758

House AA, Eliasziw M, Cattran DC, et al. Effect of B-Vitamin Therapy on Progression of Diabetic Nephropathy: A Randomized Controlled Trial. JAMA. 2010;303(16):1603–1609. doi:10.1001/jama.2010.490

So, it's probably fine, but honestly nobody really knows.

I mean yeah if you're doing heroic doses of something that you pee out, then your kidneys will be stressed out

... if you're doing heroic doses of something you can't pee out then it's a bit worse

No, megadosing B12 isn’t a universally great idea.

For example, elevated B12 levels are associated with increased lung cancer risk in a dose-response fashion: https://pubmed.ncbi.nlm.nih.gov/30499135/

The only time megadosing B12 is a good idea is if you have confirmed low levels via a blood test and need to quickly raise your levels to the normal range.

Don’t assume you can guess your B12 status by reading random articles on the Internet. Low B12 has become a favorite hypothesis among the alternate medicine crowd, so online information about B12 supplementation has become corrupted with pseudoscience.

I’ll admit that I fell for the idea that B12 deficiency was rampant due to modern diets. Then I got a blood test and discovered that my B12 levels were toward the upper end of the reference range already.

On the bright side, B12 absorption is very nonlinear. A megadose might only cause slightly more absorption than what you find in a regular multivitamin. Most of the megadose is simply not absorbed.

"megadosing" doesn't sound like its required for any reason unless you're malnourished, in which case your doctor would tell you how much to take. Adjusting your diet to not require "megadosing" due to malnourishment sounds like a better plan for long term health.

In addition, studies suggest that high levels of B6 and B12 in the blood are correlated with higher risk of certain cancers, such as prostate and lung cancer. In my opinion, having mild nutrient deficiency is not cause for alarm if you're a fully grown adult, and in fact, studies suggest that malnutrition might confer a longer lifespan.

Are those malnutrition studies about nutrient deficiency or caloric deficiency?

I do not think those are good suggestions for the average person. I've read meta analyses about low caloric intake but not about malnutrition, which in general is a bad idea.

That being said most people who aren't severely restricting the types of food they eat, and eating healthy food, are unlikely to have significant malnutrition.

The lung cancer thing I remember was specifically smokers, so its not straightforward.

>studies suggest that malnutrition might confer a longer lifespan.

There are some data suggesting that inadequate supply of this or that nutrient reduces certain aging mechanisms and leads to longer lifespans in a laboratory setting. However, outside of a laboratory setting these nutrient deficiencies can affect the body's ability to fight infections and heal injuries, which on average cancels out any benefits.

More generally, trying to increase lifespan by adjusting the diet seems to me like trying to fix a car by playing with the buttons and knobs on the dashboard. You might obtain a small improvement, but you're not really going to get anywhere unless you open the hood.

B3 overdose is dangerous if you have susceptibility to gout.

This happened to me after I inadvertently megadosed by consuming a knock-off Berocca drink containing something like 10x RDI.

That was over 10 years ago. I have not had a gout attack since.

Edited: Risk is actually for Vit B3 (Niacin). The drink I had contained massive amounts of B12, B3 and others.

https://www.mayoclinic.org/drugs-supplements-niacin/art-2036...

Megadosing B12 gave me dizziness and trouble sleeping (I had hypervitaminosis)

I do that. I drink at least one 5-hour energy drink per day. I feel less depressed when I do that, but don’t try this at home without consulting doctor. I experiment with myself a lot and know my limits.

I sure hope so because I've been taking half a serving of these little suckers for a while now: https://amzn.com/B001LXRWWE

Here's a breakdown of the DV for some of the vitamins for a full serving:

B1 = 33x (yes, 3333%)

B2 = 30x

B6 = 40x

B12= 83x

I have recently been using the Whole Earth and Sea Bone Structure multivitamin partly because it has much more reasonable doses of almost everything (except B12 for some reason):

https://www.vitacost.com/natural-factors-whole-earth-sea-bon...

They liquify plants and then ferment them in some proprietary process that they don't go into detail about (I wouldn't be surprised if they use some GMO bacteria that goes against the non-GMO advertising, since many commercial vitamins are produced by GMO bacteria). I just use two pills a day (what the chart shows data for, most vitamins from 1/3 to 2/3 of recommended daily amount). Eating a healthy diet, there should be no need for 100% or more of nutrients in a supplement, but it is frustratingly difficult to find reasonably dosed multivitamins.

Why would you need so much?

Supplement Marketing

If you do strenuous workouts frequently then this helps you recover faster and workout longer. If you are just couch potato then it’s actually detrimental and you can develop all sorts of problems including peripheral neuropathy.

>If you do strenuous workouts frequently then this helps you recover faster and workout longer.

Is that (and the amounts mentioned) based on science, or just what some gymnast dude said?

>just what some gymnast dude said

The technical term is broscience

Strenuous workouts don't cause chronic deficiency and don't eliminate chronic overdosing.

I used to run ultra marathons, when you push your body to the limit like this, you do run into limits and deficiencies, not chronically but during hours of running and this extra overdosing does help the body function better

Ultra-marathons aren't "strenuous exercise" by any reasonable definition, they're much more extreme. For most people "strenuous" involves high heart rates for a half hour or so.

Is there reason to believe that 10x vitamin B is insufficient to recover from a workout?

And to be very honest, whenever I read articles about the dangers of excess Vitamin D seems I'm reading an article on the dangers of malnourishment. In a country of obese people.

Yes, don't mega dose but you have to go out of the way and ignore all warnings and be reckless. It's the equivalent of "hey, how much aspirin should I take?" And just take a random amount

I do take it, but I know how much of the RDA that corresponds to

> pop-science articles with unbridled enthusiasm for megadosing vitamins

That's an instant red flag for bullshit.

I see Vitamin D toxicity at MUCH lower doses than in this case report. Here is my description of one patient: https://www.devaboone.com/post/vitamin-d-part-2-shannon-s-st...

Most of the patients I see with vitamin D toxicity are on 5000 units daily or more. And it can take a while (years) for toxicity to occur. Vitamin D builds up during that time since it is fat-soluble. If you want to take Vitamin D over a long period of time, at least check your levels.

Thanks for sharing this write-up.

I’m also concerned with the unbounded enthusiasm for Vitamin D supplementation in the wake of all the COVID news. The two most common mistakes I see online are:

1) Not understanding the long elimination times of these vitamins. When overdose can take months or years to appear due to gradual accumulation, it becomes difficult to associate health problems with slowly increasing vitamin levels. Most people don’t realize that overdose won’t be immediately apparent.

2) Forgetting to account for dietary Vitamin D intake. The way some people talk about Vitamin D, you’d think that supplements and sunlight are the only way to get it. If these people added up all of the Vitamin D they received through their diet they might be surprised that their combined dietary plus supplemental Vitamin D intake is higher than they wanted.

There is another one: regulation of vitamin D occurs before synthesis in the body.

Ready vitmain D from food/supplements can't be regulated by the body and all excess vitamin D will have its full effect.

Another concern with Vit D supplementation is magnesium.

As calcium and magnesium compete for absorption, Vit D’s effect of increasing calcium absorption can reduce magnesium absorption and lead to symptoms related to magnesium deficiency.

I gather the toxic effects described in the article are partly due to extreme magnesium deficiency along with other effects - though magnesium or other effects aren’t mentioned in the paper, only acute toxicity symptoms.

But it can be an issue even at much more conventional levels of Vit D supplementation, as many people are already magnesium deficient due to it being difficult to absorb from foods.

As I’ve had evidence of Mg deficiency, I’ve been taking magnesium malate for a while, but am now looking at the more absorbable forms magnesium l-threonate and magnesium bisglycinate. At times I’ve taken a supplement that combines calcium, D3, magnesium and phosphorus, to keep these nutrients in balance.

Of course one should work with a health professional when considering taking dietary supplements.

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5652077/

https://betteryou.com/health-hub/magnesium-other-vitamins-mi...

Unfortunately, magnesium has become another common target of megadosing pseudoscience on the Internet. It is possible to overdose on magnesium, despite popular belief.

Excess magnesium is eliminated very slowly, meaning overdose can happen after months of steady supplementation.

Anecdotally, gwern tracked some results after consistent magnesium supplementation and found a trend toward worsening after an initial boost: https://www.gwern.net/nootropics/Magnesium

I think we’re going to look back at this period of high-dose vitamin exuberance with a lot of regret. It’s relatively easy to hit optimal levels of all vitamins with basic attention to one’s diet. We already have several studies showing that multivitamin supplementation is slightly negatively correlated with longevity in elderly populations (or at least statistically insignificant). These people taking unnaturally large amounts of vitamins are in uncharted territory.

> As I’ve had evidence of Mg deficiency, I’ve been taking magnesium malate for a while, but am now looking at the more absorbable forms magnesium l-threonate and magnesium bisglycinate.

Two suggestions:

1) Don’t guess. Get a blood test to check for low magnesium levels. There are too many bad sources of information on the internet that attribute vague symptoms to magnesium deficiency with little supporting evidence. Getting a blood test is cheap.

2) Don’t bother with exotic higher bioavailability supplements. Just take more of the cheap stuff. If the cheap stuff has (example) 20% bioavailability and the expensive stuff has 40%, you’re almost always better off just taking twice as much of the cheap stuff.

Another complication is that the L-threonate and glycine in the more exotic formulations isn’t entirely inert. Glycine, for example, is well studied to improve sleep when taken on an empty stomach. A lot of those glowing reviews of “magnesium” for sleep are from people taking magnesium glycinate and then mis-attributing the effects of the glycine to the magnesium because they read glowing reviews of magnesium on the Internet. It’s a mess out there.

There's some validity to what you've written, but some of it is patronising and seems to attribute positions to me that I didn't convey, or indeed conveyed an opposing position.

Note that I specifically wrote "Of course one should work with a health professional when considering taking dietary supplements".

That's what I do - I have multiple practitioners, and have my levels tested periodically (blood testing is of limited value with magnesium, whilst hair testing can give a better indication, though it has its own pitfalls regarding the testing procedure and the interpretation of the data, which need to be well understood by the practitioner).

You've also focused on the risk of "megadosing", which I don't practice or advocate for any nutrient.

Indeed, the real point of my comment is that supplementing any single nutrient by itself is likely to have consequences that you'll be unaware of without really doing your research. This article focuses on the risks of "megadosing" vitamin D. I'm not sure how you interpreted my pointing out that vitamin D supplementation can lead to magnesium deficiency as a recommendation to "megadose" magnesium. I've certainly never taken magnesium in any quantity that gets close to toxicity and I'd never advocate anyone else do that.

(Incidentally, I've felt before that Gwern's approach of experimenting with supplementation of a single nutrient and looking for a single change is of limited value, as it doesn't take into account the complexity effects of that supplementation. His list of self-experiments includes a magnesium/sleep trial and a vitamin D/sleep trial, with negative results in both cases. But for the reasons discussed above, a trial involving both magnesium and vit D, and perhaps other nutrients as well would likely yield very different results, and probably ones that are far more useful).

Your comments about the efficacy/cost of higher bioavailability supplements are worthy of consideration. Though it seems contradictory to warn against "megadosing" in one paragraph but then recommending increasing the dose in another.

The particular benefit I'm interested in is passing the blood brain barrier, as the biggest issues for me are mental - e.g., anxiety and memory, for which magnesium l-threonate is said to be particularly beneficial. I would expect that increasing the dosage of a different form, which doesn't cross the BBB so effectively, would potentially lead to an excess elsewhere in the body.

To be clear, I'm not primarily focusing on magnesium; the main target of my approach to healing is currently the thyroid, and I'm cautiously taking tyrosine and iodine for that, as well as working on gut/microbiome health to improve uptake so that ultimately all nutrients can be attained from the diet so and no supplementation is needed, which is ideal as you point out. But I'm not there yet; several years of testing and work has confirmed that.

I happen to be taking magnesium for headaches and vitamin D because I'm deficient. Thanks for the info!

I’ve had a genetic test done, after being told that I have significantly lower than average vitamin d levels it turned out I’m genetically predisposed to low vitamin d and b12 absorption. So I have to supplement significantly more than what is normal.

After doing so, my colds have been far less severe then in the past. What made me go to such lengths testing myself was that I thought I was doing everything right and yet got pneumonia two years in a row.

So aside from testing your blood serum levels you should consider a genetic test to see how well you absorb vitamin d. You may benefit from above average dosage (consult your dr. Ymmv)

> So aside from testing your blood serum levels you should consider a genetic test to see how well you absorb vitamin d. You may benefit from above average dosage (consult your dr. Ymmv)

The only thing that matters is the serum level. Testing your blood levels is like closing the feedback loop. Levels too low? Increase dose. Too high? Back off.

Genetic testing isn’t necessary or even really helpful. Just get the basic serum levels tested and adjust accordingly. It really doesn’t have to be complicated.

I hate everything about this comment.

first of all, low/high levels have a cause. if it's nutrition, yeah, you're right, just measure and correct.

but you come to the conclusion that's nutrition with zero evidence supporting it, and that's annoying as hell, because it's basically shunning the door for people with real conditions that could live 10x times better if only someone would have used a more rigorous method of inquiry instead of 'just nutrition lol'

it doesn't have to be complicated, but it still have to be rigorous.

You’ve misunderstood.

Measuring serum levels is sufficient to detect and work around genetic absorption defects. No one needs to get separate genetic testing if their serum levels are within range.

Self reporting symptoms like this is highly unreliable and subject to a variety of human faults.

"The patient had been assuming very high dose of cholecalciferol since 20 months (cumulative 78,000,000UI, mean daily 130,000UI), as indicated by a non-conventional protocol for multiple sclerosis."

"This case confirms that vitamin D intoxication is possible albeit with a really high dose."

This is a truly insane dosage but all this case says is that however created this protocol is dangerously incompetent.

I guarantee if you get MS you’ll do some pretty crazy shit too, probably crazier than this.

What are you talking about? I have several family members with MS and they don’t do stupid shit they learned off YouTube.

Yeah, 130K IU / day is ~20x what's typically regarded as safe.

There's safe and safe. 20x the safe dose of cannabis will make you very stoned for a while, 20x the safe dose for alcohol will kill you. Similarly an overdose of vitamin D vs aspirin.

The relevant metric here is LD50 - but a quick google doesn't find a number for vitamin D. A wild guess would be that the patient in question could have died, though whether the odds were 50% we can't really say from just one case. But it means that 130000 UI daily for over a year is in the ballpark.

taking 20x the recommended dose of water (3-4 liters daily - 60-80 liters to compare) will kill you too.

...and people have died from it: https://en.wikipedia.org/wiki/Water_intoxication

> protocol

I wonder if that's an euphemism for "stuff they learned on youtube".

Taking 130,000UI per day for 20 months is insane. Most of the over the counter doses are ~ 5000UI.

I'm curious, as to what was the patients diet like? Vit D is a fat soluble vitamin and its my understanding that one needs to eat healthy fats for it to be absorbed by the body.

The patient was taking it as an unconventional treatment for MS. A little sympathy won’t cost you much.

most of the supplements I've seen here are 1000ui, meaning she'd have to take 130 of the pills.

It makes more sense when you realize there are liquid forms of d3 you can buy which probably make it much easier to dose really high.

In Canada at least anything over 1,000 IU in a pill needs to be prescribed (at which point I think it is an injection but I might be wrong). You’ll never find larger for sale.

That's interesting, I just had a look at my local amazon in Germany and even 50k IU caps are easily available for a few euros.

https://www.amazon.de/dp/B01H3U5ZVI/

Apparently that‘s allowed as long as they specify an RDA of no more than 1.000 IU per day (averaged) on the packaging.

In the US, was looking a week or two ago, I remember seeing 2000 IU pills available over the counter, and I think I saw 3000 IU as well (can't remember that one for sure though).

I have 5000 IU pills, OTC.

You can find the liquid version though, it would make more sense than 130 pills if you were somehow convinced that was a normal dose.

I take a 60K softgel monthly, and I believe it has vitamin D in an oil carrier.

50k is what I’ve seen some friends get for extremely low vitamin D, and on a similar time interval to your prescription. But you don’t want to be taking that every day. Let alone two to three of them.

I agree that this isn't something you'd want to take multiple times a day, for an extended period of time. that said, from the original case study, it sounds like the woman was attempting the Coimbra Protocol. Whether it works or not is another question. It also requires a very low calcium diet and close monitoring of calcium & parathyroid levels - which I'm guessing the lady did not do.

Most OTC doses are 2000IU or less

> Most of the over the counter doses are ~ 5000UI.

In what universe?

In this one, doses I've seen are around 1k UI.

Here are some 5k and 10k available OTC.

10000 IU [1].

5000 IU [2] [3] [4].

[1] https://www.cvs.com/shop/nature-s-bounty-vitamin-d3-softgels...

[2] https://www.cvs.com/shop/nature-made-vitamin-d-5000-i-u-soft...

[3] https://www.cvs.com/shop/nature-s-bounty-vitamin-d3-softgels...

[4] https://www.cvs.com/shop/cvs-health-vitamin-d-softgels-5000i...

Pretty common to see 5000IU actually. Many people living in high latitudes need to take something like that amount just to stay in the normal range.

For those interested in Vitamin D and Covid, here is a summary of the research so far: https://www.devaboone.com/post/vitamin-d-and-covid

Most countries in the northern hemisphere recommend supplimenting vitamin d over the winter anyway.

Seems like a no brainer to encourage people to start taking vitamin d now as it clearly at least has a small positive effect against covid

TLDR of this referenced article: In each and every scenario and study that is examined there is a general consensus that Vitamin D deficiency may be correlated to increased susceptibility or severity of COVID-19. The final conclusion is a word of caution that this news may cause some people to load up on Vitamin D at dangerous levels. However it also states that taking a small daily dose IS actually a good idea during Covid. The dose recommended in the article for pretty much anyone is 1000 IU during Covid.

Something missing is how fast did the patient ramp up to that dosage. If you start at a very high dosage, you will mobilize all the stored calcium in the gut and vascular system. It has to go somewhere. As some who is currently at 52k UI's per day, I can say that if I started at that level I would have damaged myself in many ways, not just kidneys. I started at 2k per fatty meal/snack and worked my way up over a few years. The purpose has been to de-calcify my vascular system and gut. I can actually tell when I am near the limit as it induces pain. I back down a few thousand IU's for a couple weeks, then keep working back up. When I first started, I could not exceed 4k per meal without getting blurry vision. Now that happens around 54-56k. I probably will not go much higher. I do not suggest doing this unless you have a good reason to do so. If you must do this, then be sure to include K2 MK-7 and magnesium for each dosage to bind and transport some of the calcium to the bone. I am not a doctor and this is not medical advise, not to mention, only a small percentage of functional medicine doctors use this method of de-calcification. My BP has dropped over 20 points, so I am making some progress. For people just wanting enough 25-hydroxy to fuel their immune system, 2x the RDA is probably fine assuming normal renal health. BTW, measuring 25-hydroxy has little value unless you know your kidney health, as that is the not the final stage of the hormone.

The idea is to push PTH to the bottom of the range. Can be done with a combination of calcium and vitamin D. Get more calcium (maximum 2:1 Ca:Mg) than phosphorus. Serum 25(OH)D at 40(-60) ng/mL or greater.

More vitamin D3 can be handled if taking higher amounts of vitamin K2 (at least 1mg MK-4 and 100 mcg MK-7 per 10,000 IU) and magnesium.

Could also add (sustained-release) melatonin if done growing to balance D3 in the AM.

I had a mini-episode of this earlier this year. Reposting as a warning for people:

I had mild Vitamin D deficiency which was diagnosed by a doctor many years ago. I was given Vitamin D supplements, which I stocked up on more than usual recently due to my staying in all day due to WFH and not getting any sunlight.

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

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

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

It seems very unlikely this was Vitamin D related. 1400iu daily is a relatively low amount. Further, Vitamin D is fat soluble, so the amount you take on a given day will have little effect on your overall Vitamin D status, as it builds up in fat over time. If you were really at the point where you had hypervitaminosis D it would have taken a long time to reduce to normal levels.

That's very surprising that something bad happened with as low as 50mcg (2000 IU). I was suggested to take that much by my doctor _daily_ without even bothering with a test (granted I'd taken a test years prior in a similar climate, perhaps that was enough for him). I even temporarily upped it for a period to 4000 IU basically for the same reason as you. And I think I've heard some people claim that as much as 5000 IU is safe without a test?

It's just surprising that this happened to you given that you're naturally deficient.

I had the exact same thing - too much thirst, even with low doses (1000-2000IU), but especially with 4000Iu or 5000IU, and really a lot with the 60kIU which the doctor originally prescribed. But the doctor advised to keep on taking vitamin D, as my levels were low. A second opinion from another doctor was no different. I did some research on my own and figured out it could be because of a Magnesium deficiency. I started taking Magnesium supplement and after supplementing for some time resumed the vitamin D along with Magnesium, and that fixed the thirst issue. If I would take vitamin D without magnesium, the thirst problem would come back. Even now if I take high dose vitamin D or even a calcium supplement without taking Magnesium, it leads to a lot of thirst. It's been a long time but from what I remember, I figured that it was because of vitamin D's effect on Calcium levels and the (electrolytic?) balance between Calcium and Magnesium in the body.

For another anecdote, I regularly get bottles of gummies which are 1500IU each (you're talking about 2000IU for reference), eating 3-6 of them a day, all through seasons which aren't summer.

I've never traced negative health effects to this. Not being a doctor, I can't give advice, but my doctor thinks this is safe, and in fact, a good idea.

Fun, but that's a lot of sugar and tooth decay when a pill would do.

It might be a good idea to go outside at lunch to get some sun. WFH doesn't have to mean staying inside 24 hours a day.

There is no data anywhere showing that 2000IU causes toxicity or harm in anyone.

Could it have been anything else?

how much is 50mcg in IU?

"One International Unit (IU) equals 0.025 mcg of cholecalciferol (Vitamin D3) or of ergocalciferol (Vitamin D2)" [1]

[1] https://walrus.com/questions/converting-units-iu-of-vitamin-...

Hmm, so 2000IU. That doesn’t seem like a lot, but I guess it really depends on the person.

It's almost impossible that their symptoms were caused by vitamin d in this case. It takes times to build up and reduce vitamin d levels, changes wouldn't happen overnight

I’ve been following this doctor for a while; he does detailed breakdowns and analyzes the available meta reviews when making recommendations: for what it’s worth K2 Mk7 (d3) is the recommended way to go.

Dr. Standfield’s video on this topic: https://m.youtube.com/watch?v=TaTsXMgS6RU

Is this report simply saying it is possible to overdose on Vitamin-D? Isn't that possible with virtually anything?

Yea I thought that was common knowledge since at least when Paracelsus said it 500 years ago:

"All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison."

Even metabolically innocuous substances can be dangerous in quantities sufficient for violent external application e.g. when being dropped[1] on one's head.

What do we call vitamin D surfeit? Arichitis?

[1] Although non-volatile storage these days is a choking hazard, in the earliest days of computing a couple of megabytes would have been fatal if their cabinet were to fall on someone.

(No lang belta this comment: Belters both have more pressing bone issues from life near the float, and get vitamin supplements from the pastes for their kibble, so unless the Belt somehow has universities somewhere and they're premeds cramming, they have absolutely no concept of rickets.)

That platitude is not that helpful. What would Paracelsus' advice be on the toxic dose of vitamin B12?

Not really sure your point. Are you saying that there is no upper safe limit for B12 for all people?

>...Case details: A young woman was treated with multiple daily doses of 1 mg of cyanocobalamin for severe pernicious anemia. After a total dose of 12 mg, she developed acne, palpitations, anxiety, akathisia, facial ruddiness, headache, and insomnia. She improved two weeks after stopping the drug. There were no sequelae nor complications.Discussion: Although these symptoms of cobalamin toxicity were unexpected and unusual, the case reminds us that the administration of any drug is not entirely safe.

https://pubmed.ncbi.nlm.nih.gov/31018715/

Vit B12 LXX kg fiat bolus sumendum ab alta oculus uterque hora somni ought to do the trick.

Determining LD50 is left as an exercise for the reader.

> That platitude is not that helpful.

And neither is a report simply saying it is possible to overdose on vitamin D.

Which was the point of the comment.

Another case-study that may be of interest has some information on effects of elevated Vitamin D levels on the kidneys:

"In terms of renal involvement, hypercalcemia can cause kidney injury both acutely and chronically.

Hypercalcemia can cause acute kidney injury primarily by 2 mechanisms: afferent arteriolar constriction and intravascular volume depletion from a diuretic effect through activation of calcium-sensing receptor at the sodium–chloride cotransporter in the loop of Henle."

Use of vitamin D drops leading to kidney failure in a 54-year-old man Bourne L. Auguste, Carmen Avila-Casado, Joanne M. Bargman CMAJ Apr 2019, 191 (14) E390-E394; DOI: 10.1503/cmaj.180465

There's a cool histological slide showing the actual calcium deposits in the kidneys that were causing some problems.

This fella had a couple other things going on as well that likely contributed to this, but food for thought.

> The recommended brand contained 500 IU per drop. Unknowingly, the patient obtained another vitamin D preparation that contained 1000 IU per drop. The patient was not counselled about toxicity risks and, over a period of 2.5 years, he took 8–12 drops of vitamin D daily, for a total daily dose of 8000–12 000 IU.

> The patient’s calcium and vitamin D levels decreased after initiation of hydroxychloroquine. Almost 1 year after diagnosis, his calcium and vitamin D levels have returned to normal, but he is left with stage 3B (estimated glomerular filtration rate 34 mL/min/1.73m3) chronic kidney disease.

Holy heck that's an insane amount of Vit D. That's 130 typical tablets a day, or over 40 per meal.

On this page it says the recommended dosage is 600 IU

https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona...

Are there any other opinions?

Yes. 2000 IU and 5000 IU daily are common recommendations from medical groups in the USA.

I take 5000iu daily. My levels are fine. They were low before I started taking vitamin d.

I live in Seattle and taking 2000 UI daily barely got me to “sligtly deficient”. Now I upgraded to 4000 UI daily hoping to get to the lower part of the normal range.

I talked to the doctor and she told me that among blood tests she ordered most people have slightly/moderately deficient levels, very few low normal, and over the years only one person tested high normal (i.e. when taking supplement would be detrimental).

Moral of the story - do a blood test, but if you live in high-ish lattitudes, most likely you have vitamin D deficiency.

and especially if you live where people don't tan, they rust.

Mind you, Seattle is the only city I've ever really liked, and I wish I could live there now.

You should test your serum D3 level first, if its fine, why take anything? If its low, take whatever gets you into the normal range. Personally, I think 600 IU isn't going to move the needle much, based on information here

https://www.grassrootshealth.net/project/dcalculator/?_ga=2....

Your blood levels tell how much vitamin d your body is holding onto. In addition to not getting enough sun you could have an absorption problem, in which case they may try other things but one of those is just cranking the dose.

My doc has had me taking 15,000 IU for four years or so. So, some other opinions.

Your doctor also had you coming back for blood work yes? High doses are meant to top up your liver. Once that works your serum levels will climb and you would cut back.

He started lower, but 15K is where blood levels were normal, and they've remained steady since. Soon we'll see if 6 months of staying inside has affected things. :)

How frequently?

Daily. Started at 5000, then 10, then 15, which is where blood work was okay.

Lol. Many

If you're interested in looking up more info, the medical term for this is "hypervitaminosis"[1], and is most common with fat soluble vitamins A and D since those can build up in the body more easily than water soluble vitamins.

[1] https://en.wikipedia.org/wiki/Hypervitaminosis

Focus seems to be on an extreme outlier case, but the title also asks the question about how much vitamin D is too much and promises a review of the literature.

Has anyone found and read the whole article? Does it suggest an answer to the too-much question based on a "review of the literature"?

I have taken 4000 IU for two months or so. My diet probably contains enough Vitamin D otherwise.

Anyway. I started to have heart palpitations / arrythmia. Stopped taking Vitamine D for other reasons (basically I forgot to buy more), heart issues went away.

I initially thought there was a mistake referring to "UI" instead of "IU", but it looks like it's a European thing. The authors' names look Italian. I guess it got lost in translation.

IU is a neat unit. Vitamins can often come in multiple forms, and each will have a different bioavailability. IU normalizes that. When you measure vitamins in mcg the dose may differ from one form to another.

Can you OD on vitamin D from getting too much sun? Or does your body have a way to turn off the production?

Same question but say you take a high supplement and then have a day in the sun?

Can you overdose on vit D from being in the sun? No.

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

UV also photo-degrades subcutaneous vitamin B in the skin so you can't OD via sunlight.

Exogenous UV not in the skin will not be photo-degraded, so supplement + sun may lead to overdose.

Based on my understanding, the main problem surrounding too much Vitamin D is with high levels of calcium that develop.

Vitamin D plays a big role as a calcium-regulatory hormone, and too much of it can lead to elevated levels of calcium in the blood.

However, in a normal, healthy adult, the body's own feedback-inhibitory mechanisms will just downregulate synthesis of the hormone when too much calcium is detected in the blood.

If you're sick or have other things going on (like cancer or taking too many Vitamin D tablets), however, it can be a problem:

Papapetrou PD, Bergi-Stamatelou M, Karga H, Thanou S. Hypercalcemia due to sun exposure in a patient with multiple myeloma and elevated parathyroid hormone-related protein. Eur J Endocrinol. 2003 Mar;148(3):351-5. doi: 10.1530/eje.0.1480351. PMID: 12611617.

https://pubmed.ncbi.nlm.nih.gov/12611617/

Use of vitamin D drops leading to kidney failure in a 54-year-old man Bourne L. Auguste, Carmen Avila-Casado, Joanne M. Bargman CMAJ Apr 2019, 191 (14) E390-E394; DOI: 10.1503/cmaj.180465

https://www.cmaj.ca/content/191/14/E390

Naik MA, Banday KA, Najar MS, Reshi AR, Bhat MA. Vitamin D intoxication presenting as acute renal failure. Indian J Nephrol. 2008;18(3):125-126. doi:10.4103/0971-4065.43693

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813130/

"Hypercalcemia is a condition in which the calcium level in your blood is above normal. Too much calcium in your blood can weaken your bones, create kidney stones, and interfere with how your heart and brain work."

https://www.mayoclinic.org/diseases-conditions/hypercalcemia....

Here's the graphic on Vitamin D synthesis in the body from Wikipedia, you can see that the enzyme CYP27B1 is inhibited by elevated levels of calcium in the blood, so calcidiol is shunted into production of an inactive metabolite. This is what would be happening if you were out sunbathing for 123123 hours per day.

https://en.wikipedia.org/wiki/File:VitaminDSynthesis_WP1531....

Yes that's true, and it's the reason that K2 pops up every time D/D3 is discussed. K2 regulates the calcium flows in the body, so that it ends up where it should be (e.g. bones) and not where it should not be (e.g. soft tissue). I take ~40mcg of K2 M7 all-trans per 1000IU of D3.

In a way. If I take a lot of vitamin D in one day (like 10K UI) I typically get chills, sweats, nausea (sometimes even vomiting) and other fever like symptoms. I think it's the effect of your body turning on its fight against infection.

I don't know if that's "OD"ing specifically. But I am replying because I get the exact same thing when I'm out in the sun all day long. I do feel like you probably can't get 130000 UIs from being in the sun in a single day.

That's called sun poisoning and it's not related to Vitamin D.

I had not heard of sun poisoning, although I've suffered it. I've been told it was heatstroke (since no sunburn), but it felt different and indeed it is (due to medicines I take). Thanks for that tidbit.

So there's this thing called polymorphic light eruption (which is a stupid convoluted science word for sunburn):

"The cause of polymorphic light eruption is unknown. It is postulated that there is a delayed hypersensitivity reaction to an endogenous antigen expressed after exposure to sunlight or artificial sources of ultraviolet (UV) radiation."

Hypersensitivity means allergic reaction. UV radiation is murking your exposed skin cells because it causes such severe DNA damage that the cells commit suicide in a process called 'apoptosis.' The body's immune system is freaking out because it's seeing a bunch of stuff all of a sudden, that has floated out of your dead skin cells, that it isn't supposed to see. It releases a ton of chemicals that make you feel nauseous, crappy, and sore, and which normally are key parts of fighting infection as part of the inflammation reaction.

Oakley AM, Ramsey ML. Polymorphic Light Eruption. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430886/

This results in:

> "Release of inflammatory markers such as prostaglandins, reactive oxygen species, and bradykinin."

> "This leads to vasodilation, edema, and pain which translates into the classically red, painful skin seen in a sunburn."

> "Additionally, skin exposure to UVB causes an increase in chemokines such as CXCL5 and activates peripheral nociceptors, which results in over-activation of the pain receptors of the skin."

Guerra KC, Urban K, Crane JS. Sunburn. [Updated 2020 Aug 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534837/

That allergic reaction is in addition to the common damage to the DNA of the skin cells caused by the UV radiation, that may occur before you get any of that pain and swelling. This is scary because if the cells are dead, ok you get a sunburn, but that's because they're dead. If the DNA is damaged and the cells don't die, you can lose genes like cell cycle checkpoint inhibitors and tumor suppressors. And BAM, melanoma which winds up killing somewhere in the ballpark of 9,000 people in the U.S. each year, as well as squamous cell carcinoma which kills like another 15,000.

https://www.cdc.gov/cancer/uscs/about/data-briefs/no9-melano...

https://www.skincancer.org/skin-cancer-information/skin-canc....

So, on average, 200ish times the recommended daily dose? No wonder she had problems.

Agreed, but her problems resolved within 6 months and VitD returned to normal within 18. Quite a difference from the doctor here on HN that has been claiming irreversible issues from taking doses far below what this lady took.

Don’t mistake the remission of serious, life-threatening anomalies in this one patient as evidence that no long-term damage was done.

In these cases, the doctors aren’t giving the patient a clean bill of health across all parameters. They’re just confirming that the immediately life threatening issues are no longer an imminent danger to the patient. It’s entirely likely that the patient suffered more insidious, long-term health consequences that aren’t immediately obvious.

It should also go without saying that the excessive vitamin D doses didn’t do her any favors. The “more is better” approach to vitamins in the alternative medicine community really needs to stop.

Hard to draw many conclusions from a sample size of 1, other than that taking megadoses is a bad idea.

I think 130 times recommended. Or perhaps only 30 times what should be recommend.

It's thought the old recommended dose is to low for some people or some situations. Which is why they really want to push it up as much as possible for all because it will save lives.

Hence these studies. I'm doing 1000UI daily given current data and covid-19.

I seriously doubt this was a scientific study to test the upper tolerance limits of vit D. I mean, no ethics committee on the planet would approve the dosage.

I was hoping to see an animal model, or on an in-vitro model:

Bao YW, Yuan Y, Chen JH, Lin WQ. Kidney disease models: tools to identify mechanisms and potential therapeutic targets. Zool Res. 2018;39(2):72-86. doi:10.24272/j.issn.2095-8137.2017.055

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5885387/

Nishinakamura, R. Human kidney organoids: progress and remaining challenges. Nat Rev Nephrol 15, 613–624 (2019). https://doi.org/10.1038/s41581-019-0176-x

https://www.nature.com/articles/s41581-019-0176-x#citeas

With a nice, simple graph showing effects of Vitamin D levels on kidney function over time.

Wow, over 150x the recommended amount. Lucky the person survived it.

This can be just MS relapse, non related to Vit D overdose.

...which is of course why the patient got better when they went off the Vit D.

When RRMS you always will be better some time later, even without treatment. Just trust me, i have this shit many years.

I've noticed this specific case being brought up on HN 3 times in the past 3 weeks (from different sources). I think it's a dead horse.

Beyond that, I would wholeheartedly recommend people take 3000 UI per day while COVID is floating around. (3 drops from your typical Vitamin D in drop form)

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