I struggle to believe that a physician told her to take 5000 IU of vitamin D daily for 5+ years. This is nearly 10x canada's recommended winter time dose for adults under 70. After years of struggling with severe joint pain and mental fog/depression, among other things it was discovered that I had critically low vitamin D. They prescribed the 5000 dose but told me at least 10 times how I should NOT continue this high of a dose after the treatment was over.
For me, the supplements were noticeable and life changing and I can tell when I have fallen off taking them for a while. But I don't approach anywhere near this dose. Seems like a case of miscommunication.
The widely used daily recommended amounts of Vitamin D (600 IU in the US and Canada) are wrong, by a factor of 10, and based on a math typo that no one caught until 2017: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541280/. I guess many still don't realize this fact.
"We call public health authorities to consider designating as the RDA ... around 8000 IU for adults"
Vitamin K is needed so that calcium doesn't build up in the vessels but goes to the bones where it's supposed to be. But, taking D and K at the exact same time reduces the absorption of D.
Not at all. Suboptimal, but far better than taking nothing at all.
There are loads of nutrients that technically compete for absorption, but generally it isn’t a concern unless you are taking a huge dose of one. Even then, it’s not like little dog is completely blocked. I’d have to look at the studies the above comment is referencing to determine how much of a concern it actually would be.
Even if taking both together was 30% less effective than taking them apart, in the context that getting people to take a single pill daily with regard to timing is hard enough, it’s still a overall win. That said, I would agree such a situation should be reflected on the label.
“Less effective” is odd here because other commenters are saying that K2 ensures D gets deposited in the right places rather than build up in the arteries (as plaques presumably). So if it is, say 30% less effective, then taking them apart wouldn’t that mean that rather than getting (example) 1,000 IU in the wrong place, you’d get 700 IU deposited in the right place, so it would be more effective rather than less?
The whole idea is that some research suggests that vitamin D may be harmful without vitamin K to offset its effects ("so that calcium doesn't build up in the vessels but goes to the bones where it's supposed to be"). That's all there is to it.
No need to discuss absorption. Furthermore, the idea "taking D and K at the exact same time reduces the absorption of D" is unsubstantiated in medical research
As mentioned, K is more to make sure the calcium absorbed as a result of vitamin D can be properly put away instead of hanging around in the arteries.
Magnesium is very important cofactor for metabolism of Vitamin D (and many other things, it’s a cofactor involved with hundreds of enzymes and such), which people are also generally low on.
I think there may be another big cofactor or two, but they escape my offhand recollection.
absolutely on the Magnesium. Due to our diets being primary processed wheat, sugar, oil, and animals, (and partially due to soil mineral depletion) our diet is persistently low on Magnesium by quite a large margin. the impact of this on the population is not consistent. this really doesn't get enough attention in the media or many other places.
https://vitamindforall.org/letter.html is a letter that goes into why >= 4000 IU daily is recommended based on blood serum levels with more literature review.
The fear of vitamin D overdose is GREATLY overblown, people recover even with overdose with ridiculous (2 MILLION) units over several weeks, anyway, it's strange how much fear has been manufactured over this particular "vitamin".
> The evidence is clear that vitamin D toxicity is one of the rarest medical conditions and is typically due to intentional or inadvertent intake of extremely high doses of vitamin D (usually in the range of >50,000-100,000 IU/d for months to years).
It's really important to follow the sources when you see something like this quoted. The article you link to is not an actual study in which people were given Vitamin D. It is a review article, and the specific sentence you quote references an article by Michael Holick, who then references two other articles. One of those articles is just a review, not citing new evidence.
The one piece of evidence that these are all referring back to is a small study done in men in high latitudes in winter, when skin production of Vitamin D is decreased. It consisted of a small number of patients who were randomized to receive different amounts of Vitamin D, so only a small number actually got 10,000 units a day, the highest dose. And this was over a period of just 5 months. You can read the article here: https://pubmed.ncbi.nlm.nih.gov/12499343/
Note that the highest dose in this study was 10,000 units a day, which I would agree can be safe for some people over a short period of time. But it was not necessary in this study to attain goal Vitamin D levels, and over time that dose can definitely cause problems.
Also, where is the 50,000 to 100,000 unit evidence coming from? I'm not sure actually, since there are no human studies looking at that dose. This may be a "theoretical" dose based on studies in other animals, or a false extrapolation based on human studies.
Also, Michael Holick is a controversial figure. A lot of the articles pushing high doses of Vitamin D lead back to him. Please read this NY Times article for a great summary of his issues: https://www.nytimes.com/2018/08/18/business/vitamin-d-michae...
> The knowledge about toxicity from hypervitaminosis D in terms of dosage and duration is limited. Because of the high heterogeneity in reported amounts of vitamin D intoxication cases, it is not possible to calculate a reliable mean value that will invariably induce toxic effects. The highest daily dose hitherto reported in the literature is about 2,000,000 UI/day that has led to intoxication in a couple of months
> Moreover, the highest cumulative dose (657,000,000 UI) leading to toxicity was obtained after 36 months of treatment with cholecalciferol 600,000 UI/day
Figured people can Google, all I bring is awareness this is widely overblown, having taken myself, for therapeutic purposes, upwards of 100k IU per day for months without doctor supervision (but doing it correctly, with a very low calcium diet). People take vit D megadoses for autoimmunity, with significant success, but I'm not discussing this here.
Since you seem to be an expert: What about different forms of vit D? I vaguely remember discussions about pills not being absorbed well. Also I remember people talking that vit D intervention fails to do anything besides raising the blood levels, indicating that things might be more complex. I'm interested in the topic, but never really dived into it.
There are only two forms, the plant/mushroom form (D2) and animal (D3) form.
As with anything fat-soluble it's wise to take it as part of a meal that includes plenty of fat.
The problem with most studies is, surely in part because of this unfounded fear, they are underdosed. I don't have anything on hand, but I know there are clinics supervising megadose vitamin D protocols all over the world, but mostly in Germany and Latin America, that I'm aware of.
It really means complete elimination or drastic reduction in anything high in calcium, even water can have quite a bit. But this was, again, with extremely high doses. I don't currently follow the protocol, as I do other things, but I sometimes take high doses for a few days.
When I had my first major flare-up, I tested at 7ng/dl (near bottom half of the severe deficiency range). That's what lead me to pay attention to this subject.
>People take vit D megadoses for autoimmunity, with significant success,
You mean for compensating for the low vit D levels due to constant inflammation seen in autoimmunity? or to decrease autoimmunity? I have autoimmune diseases and my vit D goes down to about 7 ng/mL without supplementation, so I'm curious.
That's the same level I had when I got very ill, it's near the bottom half of the insufficiency range, you should definitely consider supplementing and monitoring it.
Per your question, the latter, the theory is autoimmunity is exacerbated in a certain genetic makeup, and to compensate for it by megadosing.
This is one case report. Yes, this person took an insane amount of Vitamin D and ended up very sick from it. But we can't really conclude that amounts under her dose are safe.
does not jive with the documented case of 2M IU (50mg) per day for months, nor with this case:
> Two patients, a Caucasian 90-year old man and a 95-year old woman, were monitored from 1 h up to 3 months after intake for clinical as well as biochemical signs of vitamin D intoxication. Blood vitamin D3 concentrations showed a prompt increase with the highest peak area already hours after the dose, followed by a rapid decrease to undetectable levels after day 14. Peak blood 25(OH)D3 concentrations were observed 8 days after intake (527 and 422 nmol/L, respectively (ref: 50–200 nmol/L)). Remarkably, plasma calcium levels increased only slightly up to 2.68 and 2.73 mmol/L, respectively (ref: 2.20–2.65 mmol/L) between 1 and 14 days after intake, whereas phosphate and creatinine levels remained within the reference range. No adverse clinical symptoms were noted.
I've been on 10,000 IU daily for longer than that, its the only thing that brought me up into the normal range, and my doctor just does periodic blood tests (for either it going high or any signs of the problems that can come from it being too high) and has it listed with my current medication in my chart.
The miscommunication seems to be in her care team: symptoms associated with high vitamin D occurred, she was known to be on a high supplemental dose, but it was months of progressively worsening symptoms before anyone put 2 and 2 together.
Vitamin D seems less of the issue here than sharing and/or appropriately considering medical records
I take 12k IU of D3 + K2 to keep my calcium and vitamin D levels adequate.
Also, I have anemia of unknown etiology.
Not recommended for everyone, but supplementation should be calibrated with regular blood tests. This should be the standard of maintaining homeostasis.
There is a big difference between Canada and the US in how Vitamin D is treated.
In the US, you can go into any major pharmacy chain like CVS or Walgreens and purchase Vitamin D over the counter in 5,000 unit pills, with the bottle instructions saying to take once daily. I periodically check the Vitamin D supplements available and will find them with 10,000 units per pill, again with instructions to take once daily.
Many of the patients from the US who come to me are taking Vitamin D - and 5,000 units a day is a common dose. Most of them are told to take this by their physician, and others are on the dose because they just went to the pharmacy and picked up a bottle, which happened to contain 5,000 units.
Just a quick google search produced these 10,000 unit pills available at Walgreens, made by a common vitamin company. Note that the instructions are to take once daily, and there is no mention of watching calcium levels: https://www.walgreens.com/store/c/nature's-bounty-d3-10,000-...
I was diagnosed with low serum levels of vitamin D so I take daily supplements. The general guidance for my condition is 1000 IU daily.
At one point in time, I discovered I had been taking 5000 IU/day instead of 1000 IU/day for about 180 days because of the bottles being identical except for the dosage printed in Flyspeck Times Roman 4pt. Fortunately, I alerted my doctor and a followup blood test confirmed I was still in normal range. Scary to think how that could have been a much more serious problem if I were more sensitive.
I take 5000 UI D3 daily from October to March and blood test are fine. I wouldn't take it during sunny times if you spend decent amount of time outside.
Yea, the dosage and labeling for sure needs work. I see 2000 IU doses regularly sold in stores and the bottle says you can take 2/day. Obviously no doctor would recommend that for anyone not sick. I also get regular blood tests since, I'd guess most people using supplements do not.
> Yea, the dosage and labeling for sure needs work. I see 2000 IU doses regularly sold in stores and the bottle says you can take 2/day. Obviously no doctor would recommend that for anyone not sick.
That is simply not true. Doctors do recommend 2000-4000 IU for healthy patients all the time.
Concur - I was diagnosed with vitamin D deficiency and my doctor prescribed an initial regimen of prescription tablets at 50,000 IU and then suggested 3,000-5,000 IU daily.
Might also depend where you live. My doctor did as yours, but I live in northern New England where we don't typically expose our skin to the sun for months at a time. Perhaps doctors closer to the tropics assume at least a low level of sun exposure?
I was prescribed 3-5000 iu daily and then I changed doctors. When I asked about continuing the vitamin the new doctors said "I won't recommend doing a test because almost everyone has low vit d levels, even with daily supplements. Just keep taking the pills. As long as its not a very high dose you should be fine".
My wife has a different doctor who does regular vitamin testing, she was prescribed 5000iu and a year and a half later her tests barely read "normal", still being on the borderline.
The NHS in the UK recommends everyone takes vitamin D supplements in autumn and winter, but says "Do not take more than 100 micrograms (4,000 IU) of vitamin D a day as it could be harmful." and talks specifically about the risk of high calcium levels. https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-...
This presumably has a lot to do with latitude though - there aren't many months in the UK where I regularly walk around with arms and legs uncovered.
> I struggle to believe that a physician told her to take 5000 IU
Believe it.
When one of the most trusted vitamin companys (Nature’s Made) sells a 5000 IU single pill dosage that can be found at any drug or grocery store in the US - it nots surprising that people buy and believe 5000 is ok.
I am 6'4" (193 cm) and 240 lbs (108 kg). A big boy. I require supplementation at 5000IU to maintain ~48 ng/mL, which is just about normal.
It is impossible, at my latitude, to obtain adequate exposure to sunlight. I tried that.
My doctor said "hmmmm your vitamin d is 9... maybe that explains the all-appendage tendonitis and muscle soreness" and recommended supplementation. I really like being able to spend 10¢ per day on D3 and K2 from Amazon instead of paying for 200,000 IU injections every month or two.
It didn't sound like arrogance to me. The "if" at the start of the sentence indicates they are not asserting their conclusion as the only truth. That said, if toxicity is a large concern, it's strange that companies sell such high dosages at least without some kind of warning. I bet a sufficient warning would prevent at least some cases of toxicity
A lot of OTC medications have potential issues and interactions. That said, my primary care recommended I take vitamin D based on blood work and no one has batted an eye at my taking 5K IU. So the idea that's some widely-accepted radically dangerous dose is simply untrue. (Doesn't mean it's a wrong idea but it's not one that doctors generally accept.)
I've been on 5000 IU daily for years and my vitamin D levels came back last month as just barely within the normal range. Seems to be some people don't absorb it very well.
About 5 years ago I got a new doctor that noticed I had Ricketts level vitamin D. They say in New England everyone has a deficiency but I also spent the previous 15 summers in dark server rooms. My level was 9 on the scale they use and the cutoff level for low level is 31.
I have been taking between a 1,000 to 2000 units daily and just this year made it to 31.
My doctor looked at my labs on-line and sent message telling me to boost my intake to 2,000. I was crushed having finally made the goal of being low on the chart. I started immediately and had my appointment a few weeks later.
During the appointment she asked how much I was taking I responded 2,000 since she told me to a few weeks earlier. Her response was that I should double that.
I decided that she had already told me to double it a few weeks earlier so I didn't boost my intake to 4,000 like she prescribed. I will see next year what my level is.
I'm doing better than I have in a long time but I also gave professional systems administration.
I have no idea but think that it is not possible to get enough vitamin D while wearing long sleeves and pants most of the time. I wonder how the bedouin population fares in vitamin D.
The recommendation for 200 to 800 IU daily is for people who already have normal vitamin D levels. To correct vitamin D deficiency, modern sources recommend a minimum of 1,500 to 2,000 IU daily [1]. The Endocrine Society even recommends 6,000 IU daily [2], so 5,000 IU is not crazy by any means. There is also nothing crazy about five years of supplementation: Many people won't maintain normal vitamin D levels even after five years of 2,000+ IU (unless they make lifestyle changes like being deliberate about spending more time in the sunlight) and they may need to continue vitamin D repletion indefinitely [2, 3].
5,000 IU is probably a bit much to give without rechecking the vitamin D level at least once a year or so, but at least to me it's not obviously medical malpractice. If there is medical error here, it's ignoring calcium levels higher than 11 mg/dl for months and the fact that the patient had to refer herself to an endocrinologist because her PCP did nothing about it.
Overall, I really don't like this article. The author is generalizing based on outlier cases. She even admits this: "Of course, there is a selection bias in who comes to me. 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." She uses "hormone" as a sort of scare word, kind of how "chemical" is used in other contexts. Sure, there are some hormones that can be very harmful, but there is nothing inherently wrong about taking hormone supplements, even for an extended period of time, just like there is nothing inherently wrong about consuming "chemicals."
I strongly disagree about restricting over the counter vitamin D. Tylenol and ibuprofen lead to thousands of hospital admissions and hundreds of deaths per year, and yet we freely give them over the counter. If vitamin D doesn't meet the threshold for OTC, then basically nothing does.
Parts 1 and 3 of the series are better. I agree that the evidence on vitamin D for most things other bone growth in children and osteoporosis is weak.
[1] https://www.ccjm.org/content/89/3/154 ("Increasing and maintaining the 25(OH)D level consistently above 30 ng/mL may require at least 1,500–2,000 IU/day")
[2] https://academic.oup.com/jcem/article/96/7/1911/2833671 ("We suggest that all adults who are vitamin D deficient be treated with 50,000 IU of vitamin D2 or vitamin D3 once a week for 8 wk or its equivalent of 6000 IU of vitamin D2 or vitamin D3 daily to achieve a blood level of 25(OH)D above 30 ng/ml, followed by maintenance therapy of 1500–2000 IU/d")
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2912737/ ("Regardless of initial vitamin D therapy, and assuming no change in lifestyle or diet, a maintenance/prevention daily dose of 800 to 2000 IU or more will be needed to avoid recurrent deficiency")
I wrote the article because I see cases like hers pretty frequently. She is an outlier in the severity of her symptoms, but not an outlier in getting Vitamin D toxicity from 5,000 units daily. I get at least one patient a week contacting me about their high calcium levels - and when I get into their medical history it is clear that Vitamin D is the cause of the high calcium. In most cases, they are on 5,000 units daily.
Some people need higher doses of Vitamin D because they have problems with Vitamin D metabolism. Those people are outliers as well.
And there are people who can take 5,000 units of Vitamin D over a prolonged period and still have normal calcium levels. The key here is that they are checking calcium and Vitamin D levels.
For most people who need Vitamin D, a dose of 1,000 to 2,000 units daily is more than enough. None of your articles contradict that, and actually that is the dose they are recommending.
I think we're on the same page that this is ultimately an issue of not following up the levels. Actually, it seems that it was worse than that - multiple physicians over a span of four months saw the calcium level > 11 and didn't act on it. (Imagine if it was a hypercalcemia of malignancy with that much diagnostic delay.)
I guess your argument is that a medication that requires a provider to order follow up labs shouldn't be OTC. My counter is that there are probably at least one to two orders of magnitude more people hospitalized for NSAID induced renal injury annually than there are people hospitalized for vitamin D induced hypercalcemia. Maybe those people could be saved from renal injury if their PCP followed their creatinine, but if we set the bar at that level than virtually no medication would qualify for OTC. This is an era where patients expect more autonomy, including the ability to self direct treatment with lower risk medications. You're absolutely right that vitamin D shouldn't be billed as zero risk, but it's certainly low risk.
As to vitamin D being a hormone, I think that's neither here nor there, especially if the question is whether vitamin D should be available OTC. I think patients tend to mentally translate "hormone" to steroid sex hormones or HGH, since those are the ones that they read and hear about in the media. Those have a lower therapeutic index and broader constellation of side effects than vitamin D does. So even though it is completely accurate to call vitamin D a hormone, it's a term that is overloaded with so much baggage that I don't think it's useful for communicating with laypeople.
Anyway, I disagree with those points, but I do think parts 1 and 3 of your article series were quite good. I have to admit that I didn't realize some labs set the upper limit of normal for 25(OH) that high, so part 2 was a learning point for me as well.
I had vitamin d deficiency and they prescribed a 50,000 IU pill to take once a week for 3 months, then said 5000 IU daily after that would be fine.
What qualified as deficient also changed during this time too. The recommendation doesn’t surprise me and the vitamin stuff has always seemed like they didn’t really know what they were talking about imo.
In India the standard of care used to be (unsure if its still the case) of a bolus dose of 60,000 IU once a week, for a month, after which you switch to taking the 60,000 IU once a month.
I've been taking 5,000 IU daily for 5 years. Got bloodwork done last month and I was at 63.7ng/mL, so I will cut back now to ~2,000/day especially with summer coming around. 5 years ago I was at 14ng/mL and the supplement seems to have helped my energy levels, gut health and immune system.
That’s most likely because Canada’s RDA for this is far too low. I take 5000IU daily during winter. I know this is the right dose for me because I actually test my blood for vitamin D deficiency twice a year, and 5000IU puts it smack dab in the middle of the normal range. In the summer I take 2000IU.
*Of course, there is a selection bias in who comes to me. 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.*
I am also doing 4000IU in the half-autumn/winter/half-spring time and none during summer and doing blood work to test the levels and I am keeping it in 40ng/ml and from the article:
*...her blood Vitamin D level had risen to 79 ng/ml. This level is within what many labs call the normal range, between 30 and 100 ng/ml, but levels above 70 are almost always a result of high dose supplementation, and I have seen toxicity with levels between 70 and 100 ng/ml. (A better “normal range” based on what I have seen would probably be between 30 and 60.) Vitamin D builds up over time, so the longer someone is on a high dose, the more likely she is to develop toxicity.*
Lady in the article was taking 5000IU daily for 5 years.
They make it sound like 5000IU is something astronomical when in reality for many people who live in the less sunny climates and have office jobs this is the normal amount. Still, one needs to test in order to see what _their_ normal amount is
Would you struggle to believe that I took 50k IU daily for over a year with no side effects? Or that others have accidentally taken significantly more than that without issue? With vitamin D, absorption varies a lot between individuals. And the recommended doses that people frequently throw around are generally just a low-ish dose that is guaranteed not to be harmful. This misleads people into thinking that such a dose is the upper bound on the set of non-harmful doses, which is not even remotely true. Honestly I find it shocking that this woman developed hypercalcemia at 5k IU daily, the only explanation for this is that she has an unusually high absorption.
5000 IU is 10x the recommended dose? I'm Vitamin D deficient (though not Canadian) and currently have a prescription for 1000 IU daily regardless of season, and that's the lowest dose I've been on in a while.
You can literally get 10,000 IU of vitamin D a day from just being out in the sun, particularly if you're fair-skinned. That would suggest that people who work outdoors would be chronically overdosing.
Vit D is fat soluble and will stay in the body a long time. Short term big bursts if you're deficient are probably fine, but more than 2000 IU a day for years makes me nervous.
for comparison, Vit C is water soluble and you can slam Emergen-C 2000 mg packets without issue as long as you're hydrated and have working kidneys -- you'll pee it out.
Yes, it's fat soluble, and you don't lose fat soluble vitamins in urine the same way you do with vitamin C, but that's only a small part of the puzzle.
Questions you should ask:
1. OK, so fat soluble vitamins aren't excreted in the urine. But are there other processes by which the vitamin is consumed? Because if so, you could quickly run short on the vitamin whether or not it's fat soluble. If deficiency of the vitamin is known to be widespread, that's probably a sign that there is some form of consumption process like this.
2. What is the mechanism of toxicity? This matters because if the mechanism of toxicity is different than the normal mechanism of action, the dose you need to reach toxicity could be orders of magnitude higher than the dose you need to reach physiologic activity.
Regarding point 1: Vitamin D is inactivated inside mitochondria.
Regarding point 2: It's hard to get vitamin D toxicity because active vitamin D (calcitriol) is created "on demand" by cellular processes by tapping a much larger reserve of inert substance (calcifediol). Vitamin D supplements increase the amount of inert substance, not the amount of active substance.
> The evidence is clear that vitamin D toxicity is one of the rarest medical conditions and is typically due to intentional or inadvertent intake of extremely high doses of vitamin D (usually in the range of >50,000-100,000 IU/d for months to years).
This article was written by my wife a while back. It is part of a series she wrote to help people think about Vitamin D. She's actually doing a facebook live presentation (and taking questions) on Vitamin D next month if anyone is interested [1]. She's doing consults all day today and tomorrow but I'll let her know this is here.
I would be interested to hear her responses to a number of the concerns/confusion mentioned below.
It seems like there is a lot of speculation in this area (not just this thread, but previous threads on vitamin D), and not a lot of evidence/studies to back it up.
Hey there! I'm here now and will try to respond to everything brought up. Some of the confusion stems from the complexity of the issue. There has been a lot of research on the clinical role of Vitamin D, much of it of questionable quality. On the basic science of it, there is a lot of great research, but these articles are often hard to read unless you have a PhD in biochemistry.
This is very confusing! Our skin can make lots of vitamin D. Lots if not more than this case describes. A quick search yields the following:
"A whole body exposure to UVB radiation inducing the light pink color of the minimal erythema dose for 15–20 min is able to induce the production of up to 250 μg vitamin D (10,000 IU)"[1]
Surely naked homo sapiens got a bigger dose wandering around the highlands of Ethiopia 100,000 years ago. What kind of perverse logic led to setting the RDA to 600 IU daily?
It makes no sense. The patient didn't have hyper parathyroid disease either! Very weird.
In the case of sunlight exposure to UVB an equilibrium is reached where the amount vitamin D produced in the skin equals the amount destroyed by UVB. This does not happen if you pop vitamin D pills. I've recently written an app that calculates the time required to obtain adequate vitamin D by lying prone in the sun, with most of your clothes off, and using MED the minimal erythema dose as a guide to safe sun exposure. At the height of summer it is a surprisingly short amount of time that is required to get adequate vitamin D even for people with dark skins.
When I look through some abstracts on NIH/NCBI, PNAS and so on I feel like there is some regulatory mechanism involved when production happens in the epidermis via UVB.
Maybe the same regulation mechanisms dont apply with oral intake, bringing Vitamin D directly into circulation without any further governance?
> "A whole body exposure to UVB radiation inducing the light pink color of the minimal erythema dose for 15–20 min is able to induce the production of up to 250 μg vitamin D (10,000 IU)"[1]
So when you expose someone to light until they get a sunburn, they produce up to 250 ug. 80 ng/ml serum is still equivalent to 400+ ug and that's in the blood alone.
The real issue is that over time that elevation caused calcium levels to rise. That can't happen with light exposure because you adapt to it.
> Surely naked homo sapiens got a bigger dose wandering around the highlands of Ethiopia 100,000 years ago.
Did they? They were black. If the "natural" level of vitamin D was significantly higher than modern levels in white people, current day black Africans would have higher levels than the RDA- they wear shorts and tshirts, so they should still have >50% of prehistoric levels. But in fact if anything people in Africa tend to have lower vitamin D levels than the rest of the world, and certainly much less than eg the US: https://www.thelancet.com/journals/langlo/article/PIIS2214-1...
On top of that, European-descended people have less efficient calcium utilization due to higher availability. They need more vitamin D to utilize the same amount of calcium, so looking at prehistoric levels is not a great indicator.
> What kind of perverse logic led to setting the RDA to 600 IU daily?
Well for one thing its certainly done with an assumption of daily sunlight exposure, since people don't usually figure that into their diet.
If you want the full logic, you can read the 1116 page book by the Food and Nutrition Board of the National Academies of Sciences, Engineering, and Medicine. They chose the number: https://nap.nationalacademies.org/read/13050/chapter/1#xiii
> current day black Africans would have higher levels than the RDA- they wear shorts and tshirts, so they should still have >50% of prehistoric levels.
Shorts and t-shirts? Em, a rather large amount of modern urban African spends most of their day indoors and wears long-sleeved shirt/pants/long dresses/long robe/hijabs/etc.
I'm not sure why one would expect them to have >50% of prehistoric levels.
The paper you linked to (or really, the metaanalysis it cited) showed low D levels were associated with urbanization, but the lowest concentrations observed in northern African countries and in South Africa with seasons. The highest levels were among those practicing traditional lifestyles.
It's not reasonable to connect vitamin D to anything 100k years ago when vitamin D is so heavily influenced by diet and weather, both of which changed wildly. Lactose tolerance, megafauna, fishing, the last glacial maximum- just 20,000 years ago people were undergoing massive differentiation in vitamin D production and utilization.
> The only lingering effects appeared to be a wariness of physicians and distrust of vitamins, both understandable
I am not a doctor, by any stretch of the imagination. But I do work on cars, and computers. As far as I can tell, a doctor works exactly the same way as a mechanic or a computer technician. They listen to symptoms, make an educated guess at a root cause based on limited information, make an educated guess at what might resolve the situation, and then wait to hear back if that fixed it; if it didn't, the loop continues.
Medicine might be scientific, but the practice of medicine is clearly an art, not a science. I don't trust my mechanic; why the hell would I trust my doctor?
> They listen to symptoms, make an educated guess at a root cause based on limited information, make an educated guess at what might resolve the situation, and then wait to hear back if that fixed it; if it didn't, the loop continues.
Having been a mechanic and having worked with a lot of MDs, unfortunately, neither profession really works that way anymore.
Mostly, you're taking symptoms, yes, but then you use a computer system to 'help' educate your guesses. By 'help' here, I mean that most mechanics and MDs just kinda blindly plug the symptoms into the computer and then start reading.
These systems have pretty detailed stats on the possible causes and fixes, what you should go check out again to get more data for the computer, etc.
Both sets of systems can pretty reliably turn a C level person into a B+/A- level person. As such the subscriptions are worth every penny.
Gaining expertise in cars/computers doesn't really translate to health medicine. It's a fallacy that I saw first hand, that say, some one gains expertise in one thing then feels confident to take on another in DIY spirit. A concrete example is someone who builds a shed that thinks they can do a bathroom renovation/remodel or build their own cabinets (don't look at me :P).
Having to throw in the towel and hire a professional I saw:
- How experts do things much faster (literally 1/3rd the time).
- How experts avoid conflicts ahead of time/or deal with them as they arise quickly
- How experts know the name of all the things ahead of time
- How experts realize when a problem is out of their wheelhouse and requires a referral (electrical/plumbing/etc).
I had to call it quits mainly because the DIY spirit is instilled into me by my father and love for tinkering. But I see it in my father, he tries to repair his own cars (with good results), because in his words mechanics are a scam and for the longest time I kind of assumed so too, but the truth is expertise is invaluable and what you are paying for is time/knowledge.
You don't expect yourself to go to med school to diagnose your problem, someone has already done that and you can leverage that.
"supplementation was associated with a significant lower risk of both Covid-19 severe disease (SRR 0.38, 95% CI 0.20–0.72, 6 studies) and mortality (SRR 0.35, 95% CI 0.17–0.70, 8 studies)"
Note that in "part 3" devaboone says Vit D failed to live up to its expectation and she posts a graph showing that Vit D only works to counter Vit D deficiency.
Since then a study came out, studying 200 000+ individuals (which is 10x more than the biggest study in the studies she cherry picked in her part 3 if I'm not mistaken), showing that Vit D supplementation did (and does) help combat the worst disease the world has known in decades (if not centuries).
Time to update the studies used in her "part 3" to conclude that Vit D supplementation only helps fixing Vit D deficiency?
For my casual reading of that study I linked to is this: those who told people to start taking Vit D supplementation during Covid did actually save lives and did actually help many have less severe symptoms.
I do think that that ship has sailed: we now know Vit D supplementation does work.
We can nitpick on whether 1000 IU or 2000 IU per day is too much or not but I don't think that saying that "Vit D supplementation only works at fixing Vit D deficiency" is a serious take anymore (once again: Part 3 clearly shows a graph saying just that).
I think doing an update would be great, when I have time. Just a note: the article you cited was not a randomized controlled trial. It is a meta-analysis that included only 2 small RCTs and a ton of observational studies.
The image from my post that you are referring to is looking only at RCTs. In RCTs, Vitamin D supplementation rarely shows a positive effect. This does not mean that Vitamin D supplementation is useless.
Even in my post from 2020, I mention that respiratory illness is one area that has shown a benefit of Vitamin D. Here is what I wrote:
"The areas in which meta-analyses have identified benefits from Vitamin D:
Fracture prevention in elderly nursing home residents (when also given with calcium): This is not surprising. We know that Vitamin D and calcium can prevent bone loss in severe Vitamin D deficiency. Elderly adults who are not getting outside are more likely to be severely deficient in Vitamin D, and supplements likely help.
Asthma and respiratory infection: Vitamin D seems to reduce asthma attacks in adults with mild to moderate disease, and daily or weekly Vitamin D seems to prevent acute respiratory infection in those with Vitamin D less than 10 ng/ml (25 nmol/l). There is considerable excitement around Vitamin D's potential role in Covid treatment, though we do not yet have enough evidence to make a definitive conclusion.
Cancer mortality: Vitamin D does not appear to prevent cancer, but may reduce death rates from cancer overall (when all cancers are combined) when Vitamin D is taken for several years. It is not known whether Vitamin D itself fights cancer. It could also be that individuals with cancer are more prone to developing severe Vitamin D deficiency, which leads to bone loss, fragility, and fractures, which increase mortality.
Atopic dermatitis (eczema): Vitamin D supplementation may prevent exacerbation of eczema. There are only a small number of trials, with small numbers of patients, so this requires more research."
We do have more information on Covid and Vitamin D now, and I would agree that Vitamin D was likely beneficial for some people. I would also add that I had a bunch of patients come in with high calcium because they started high-dose Vitamin D during Covid and never decreased the dose.
> Vitamin D is a steroid hormone, in the same category as sex hormones like estrogen and testosterone, and glucocorticoids like the stress hormone cortisol. Steroid hormones are all made from cholesterol, and looking at their molecular structures, you can see the similarities
Does it matter that 2 different things have a similar molecular structure? Surely a tiny little difference can have a huge difference in how a substance interacts with our body?
It can, in this case our body can swap the "dangly bits" of cholesterol to something different like vitamin D. Aside from this, it also depends on the receptor in question. Some receptors can accept levo and dextro molecules even though they are mirrored and therefore different shapes, while some have higher affinity for one and the other basically doesn't fit at all.
Interesting stuff, I hear people advocating vitamin D supplement all the time. I'm wary of supplements in general so have mostly avoided it but never realized it could be dangerous (I tend to think I should be able to get everything I need from my diet)
> (I tend to think I should be able to get everything I need from my diet)
I should note that pale skin is a mutation developed because Europeans in a certain range could not get sufficient vitamin D from their diet, which was mostly cereal crops.
Also, disease can change things. A family member had leukemia and after it was in remission, she has needed to take very high levels of vitamin D to maintain recommended blood levels. Her required supplementation is high enough that her doctor has her take regular blood tests to make sure it doesn't go too high.
That advocacy makes sense for a lot of Americans. A combination of living in latitudes north of 45 degrees and the general trend of people moving to work indoors really depresses natural generation of the vitamin for a lot of people.
But as with so many other things, it's not hard to go overboard.
I live in a place where there is very little sunlight during the winter, and take occasional vitamin D supplements. My supplement is 1000 IU. I took a look on amazon and of the first page of results, most were 1000IU and some were 2500 IU
It sounds like the upper end of the recommended range for Vitamin D blood levels is much higher than it should be, and that is the primary reason the person mentioned here had the problems she had, but it also just seems like common sense that you're taking 2-5 times the normal supplementation dose of something, daily, for 5 years you should have a very good reason to do so.
I'm curious if taking 1000 IU every few days could cause similar issues in people who aren't in the sun all day every day.
I think so, but I'm not 100% sure how it was producing cognitive effects. Most doctors don't seem to recommend K2 in addition to D3. Vitamin K would have helped to channel calcium into her bones and out of her soft-tissues. This would have helped significantly with her osteopenia and would have lowered her blood serum calcium levels.
The other thing that the article omits is that overweight people don't metabolize Vitamin D as effectively. It gets stored in fat. So if this subject was thin or in excellent shape, that would have been a factor in determining the proper dosage as well.
I'm currently taking 10,000IU per day in an effort to control psoriasis, but it's a bit of guess work really and trying stuff to see what helps. It's somewhat annoying that I've had a dermatologist order some blood tests, but they were only targeted for whether I can safely take acitretin (a retinoid). I wish there were cheap home-tests for various blood levels of minerals and vitamins like there are for things like glucose and uric acid (I occasionally get gout if I eat too much oily fish or asparagus).
Edit: just found that there are ones for vitamin d - shame there don't seem to be calcium ones.
We don't really have evidence that vitamin D supplementation has any effect on psoriasis. This large review and meta-analysis from 2023 by Formisano et al [1] is a very good paper on the subject.
It's true that studies regularly show that vitamin D deficiency correlates with psoriasis disease severity, at least when it comes to plaque psoriasis. But when patients are given vitamin D to normalize levels, their psoriasis tends not does not improve. (We have a tiny handful of studies that do show improvement in symptoms, but they are small and of poor quality.)
It may be that severe psoriasis simply causes vitamin D deficiency, e.g. by disrupting the skin's ability to synthesize vitamin D (which normally builds up and is released upon exposure to sunlight), rather than vitamin D deficiency causing psoriasis. There's at least one study that shows that people with psoriasis tend to avoid the sun more than other people.
One of the problems with psoriasis is that it seems to behave differently for different people and also changes over time too which makes it very much a case of trial and error to find what treatments work for people.
There's definitely a link between psoriasis and vitamin D, but as you state, it's not necessarily a deficiency that triggers it. However, anecdotally there's people who do benefit from taking vitamin D3 (along with K2 seems to be a popular combo) so I think it's worth a shot though I have tried it in the past without much success (that wasn't erythrodermic psoriasis though).
I've definitely noticed that sun exposure does help with plaque psoriasis and most people will see that their condition worsens over winter - that may be due to lower sunlight levels or cold, dry air exacerbating skin issues. And yes, psoriasis does affect people's self-image, so it can be embarrassing to expose skin when it looks like you've got some kind of plague.
True, and I would never go as far as saying that the benefits have been disproven.
I do hear about many people trying to treat their psoriasis wit vitamin D, but not about many success stories.
As far as we know, the reason sunlight helps psoriasis is not vitamin D, but because UVB at specific wavelengths has an immunosuppressive effect on the skin. It induces apoptosis of T-cells and promotes keratinocyte differentiation.
> I do hear about many people trying to treat their psoriasis wit vitamin D, but not about many success stories.
It seems to my non-expert opinion that it's a piece of the puzzle, but there's a lot more other pieces. It seems to be often linked with selenium deficiency and I've read one case of a really bad erythrodermic patient that was treated with calcium.
I successfully treated my eczema with Vitamin D. It did take several months to clear up, but now I can eat what I want with no risk of a flare-up. I took 5000IU daily. I still take it now, but only a couple of times a week.
It doesn't work for all cases of eczema or psoriasis, unfortunately; many people I have recommended it to did not have the same response.
Best of luck - I hope your Vitamin D experiment works out for you!
Taking vitamin D daily did wonders for my psoriasis. Over the years it had gotten to the point where I was breaking out in patches all over my body, and only getting worse as time went on. I went from like 2% coverage to 20%.
Started taking vitamin D and am now back at 2% (where it has sat for 4 years now since I started).
I had an outbreak of erythrodermic psoriasis (usually just have mild plaque psoriasis) over the winter and had it all over my trunk, arms and legs - approx 80% coverage. Luckily it wasn't as severe as it could be (no hospitalisation necessary), but I had a lot of trouble with body heat regulation for a while.
I ended up using topical steroids which cleared it up remarkably quickly, but am now trying to reduce my usage of that (stopping steroids can be a trigger for erythrodermic psoriasis) which has led to it becoming more pronounced again.
It's useful for normal plaque psoriasis, but I'm currently recovering from an erythrodermic psoriasis episode and UV light is not recommended for that. Psoriasis can be a tricky condition, as too much UV light (i.e. sunburn) can trigger it - UV therapy usually has to be carefully controlled.
I am merely a layperson/patient with vague anecdotal experiences, but the notion that Vitamin D is capable of complex unexplored interactions is also my belief.
For me, occasional doctor-prescribed monthly slow release doses, intended to help counter depression and seasonal-affective-disorder, instead prefaced weeks/months of arguably mild but disturbing effects after each dose. That is, weird abdominal sensations/pressure, weight loss, paranoia/hypochondria and feelings of doom, among other things. Accordingly I eventually went through a slew of tests, including every blood test under the sun and an ultrasound - nothing found, and calcium levels not elevated.
It only happened 3 times, and I only got really suspicious on the third occasion, due to the common factor of the Vitamin D dose taken prior - at which point I swiftly and permanently ceased taking it - which was not really enough time to be certain of the cause, but I sure spent some fraught hours researching Vitamin D at the time - which convinced me of it's complex potential, in a similar manner as this article - and ultimately the particular, temporary syndrome I suffered on those occasions (whatever the cause) has not recurred in the years since.
In a recent blood test my Vitamin D was low, that is the second time it happened. First time were during the pandemic, where my doctor at the time told me several people were experiencing this due to lack of sunlight (everyone was locked at home). Anyways, I'm now taking 7000ui vitamin d supplement for 6 weeks; Thanks for the article
I have recently gotten much more invested in my health, and that has lead to me cutting basically every supplement I was taking short of a few that are really excellent and well studied.
On the back of some vitamin D bottles, you'll see warnings about taking it if you have high calcium levels because it could lead to cardio vascular issues.
While most people considered the risk of supplementation to be low, there appears to be cases where that isn't the case. Be careful.
A lot of supplements are also mislabed or incorrectly dosed, because the regulations are quite lax. So even if a supplement makes sense in theory, you don't know what you're getting unless the manufacturer follows the Good Manufacturing Practices and does some kind of third party testing.
The takeaway here is that you need regular blood work if you supplement vitamin D. The variance in need is too high between individuals to rely on a doctor's hunch. Take the lab results over the "expert" opinion.
Before taking any vits I try to identify vitamin deficiencies through blood tests. I am afraid to take it freely after the incident of omega 3 poisoning...
> Professor Pennington also pointed out that a bean sprout farm in northern Germany was identified as the most likely source of many of the infections in the E. coli outbreak that left 22 people dead in 2011.
If you have a 2x2 south-facing outdoor space you can grow a variety of leafy greens in a container, and even stack containers. You can probably grow them indoors too but enough light can be challenging. (There's always grow lights tho)
Bean sprouts are well known to be dangerous when eaten raw.
'Such infections, which are so frequent in the United States that investigators call them "sproutbreaks", may be a result of contaminated seeds or of unhygienic production with high microbial counts.'
so all the people discussing appropriate vitamin D levels should also be considering where people live, their typical sunlight exposure, and/or other factors.
My USA health insurance used to cover the blood test for vitamin D, but stopped about 10 years ago. Now to get a blood test it's somewhere in the $70-100 extra range if I want to get that in addition to a normal yearly physical blood panel.
Yes, that prices isn't that much for your health, but if you decide you want to take a LOT of vitamin D then you need to comprehend the blood test costs.
I’m the author. In reading the comments here, there are some common questions and misunderstandings that I would like to address.
First, about the patient being an outlier:
I wrote the article because I see cases like hers pretty frequently, and it’s frustrating. She is an outlier in the severity of her symptoms, but not an outlier in getting Vitamin D toxicity from 5,000 units daily. I get at least one patient a week contacting me about their high calcium levels - and when I get into their medical history it is clear that Vitamin D is the cause of the high calcium. In most cases, they are on 5,000 units daily. Stopping the Vitamin D allows the calcium to drop back to normal, though it usually takes a few months.
Regarding those of you on high doses who are doing just fine:
I believe you. This actually doesn’t change the point of my article. I even state in there that some people can take high doses and not develop any problems. And some people need higher doses of Vitamin D because they have problems with Vitamin D metabolism. In addition, there are people on higher doses because they are treating other medical conditions like psoriasis. The point of my article is that you need to monitor your calcium and Vitamin D levels if you are going to take these higher doses. And you need to know the risks of taking high-dose Vitamin D over a long period of time. There are risks to any medication; treat Vitamin D like the medication that it is.
About the multiple studies posted here with statements that high-dose Vitamin D is safe and toxicity is rare:
It's really important to follow the sources. I cannot say this enough. Most of the articles cited are review articles that are simply repeating things from other review articles. You have to keep following the citations back to find the actual studies in which humans consumed Vitamin D.
When you do that, you find very few human studies on high doses. The larger studies on Vitamin D will typically use more moderate doses, such as 2,000 units daily. Most of the articles on high doses are case reports in which someone took outrageous amounts of Vitamin D and eventually got really sick from it. These case reports don’t tell us where the safe level is, only that some people can tolerate outrageous doses for a short period of time.
But isn’t there an actual study showing that high doses are safe? One controlled study that many of the review articles refer back to is a small study done in men in high latitudes in winter, when skin production of Vitamin D is decreased. It consisted of a small number of patients who were randomized to receive different amounts of Vitamin D, from none to 10,000 units daily. Only a small number actually got 10,000 units a day, the highest dose. And this was over a period of just 5 months, in the winter, in high latitude, when it is difficult to get skin production of Vitamin D. You can read the article here: https://pubmed.ncbi.nlm.nih.gov/12499343/ Also note that in this study, they found that adequate Vitamin D levels were maintained with doses well under 10,000 units daily.
A few of the review articles lead back to Michael Holick, controversial figure. He is well-known for pushing high doses of Vitamin D. Please read this NY Times article for a great summary of the issues here: https://www.nytimes.com/2018/08/18/business/vitamin-d-michae...
Regarding skin production of Vitamin D and why you don’t overdose on the sun:
Others mentioned this in their responses, but just to reiterate: you can’t get toxic levels of Vitamin D from being in the sun, because of the complex interactions that occur with UVB exposure. For those who want a very detailed explanation, read this article: https://www.tandfonline.com/doi/full/10.4161/derm.24494. TL;DR version: after a certain amount of previtamin D and Vitamin D3 is made as a result of UVB radiation, excess exposure then causes breakdown of these into products that are inactive, so you get to an equilibrium where you can’t make more Vitamin D even with more sun exposure.
And for those who think I am somehow anti-Vitamin D:
I take Vitamin D, and recommend it to patients all the time (unless they have high calcium). I recommend moderate amounts, since for most people a dose of 1,000 to 2,000 units daily is more than enough. I do have patients who need to take much higher doses, and I have some patients on 5,000 units daily who are doing just fine. There are even rare patients who need more than that. The key here is that I’m monitoring their calcium and Vitamin D levels, and I only recommend 5,000 units daily if there is some evidence that they require it.
About selling high doses in pharmacies:
I really don’t like that in the US you can pretty easily buy 10,000 unit Vitamin D pills over the counter at common pharmacies (example: https://www.walgreens.com/store/c/nature's-bounty-d3-10,000-.... I would prefer that pharmacies sold Vitamin D in doses of 1,000 or 2,000 units, rather than 5,000 units, since the lower doses are almost always safe, but the higher doses may not be. Someone mentioned that Tylenol and ibuprofen are also dangerous, but available over the counter. This is not exactly the same thing, since those bottles are generally very conservative in how much they recommend taking, with strict warnings about not taking too much. This is not the case with most Vitamin D bottles.
I'm a bro-scientist on this subject, and often suggest others supplement with Vit D because, "it probably won’t hurt, and it might help".
While I have generally suggested people take somewhere between 1,000 IU - 4,000 IU daily, I do always suggest people test their blood levels if taking doses in this range because toxicity can very occasionally occur if you're taking doses above 2,000 IU daily. Anything above 5,000 IUs daily and you're almost certainly taking too much.
I think it's worth remembering that in the Northern hemisphere a significant percentage of people have Vit D deficiencies in the winter and about 50% of people have insufficient Vitamin D levels.
Long-term having insufficient Vitamin D levels can increase your risk of cancer, heart disease and various other chronic diseases.
Given we're just coming out of winter in the Northern Hemisphere, if you're not currently supplementing Vit D and you're reading this comment from somewhere in the Northern Hemisphere there's a greater than 50% chance you currently have insufficient levels of Vit D.
Here in the UK the NHS warns against taking more than 4,000 IU of Vit D daily if you're an adult, and generally doses of 1,000 IU - 2,000 IUs are suggested to maintain adequate Vit D levels. I think these are on the high end if I'm honest, but the fact the NHS says this would suggests that 4,000 IUs daily in adults is probably generally tolerable which roughly correlates with the research and personal experimentation I've done on this subject.
Supplementing with 2,000 IU daily is almost never going to cause problems in an adult. Personally I supplement with 4,000 IUs daily in the winter and generally drop this to 2,000 IUs in summer, and I know from testing this keeps my Vit D levels slightly above the recommended 50 ng/mL all year round (although imo 70 ng/ml is a better target). I will note though that I get very little sun exposure so what I take is probably on the higher end of what's needed to maintain healthy levels of Vit D.
I'll also note that typically toxicity won't occur in most people until they reach levels greater than 150ng/ml and I get no where near this despite taking a rather high daily dose for years.
What I'm trying to say here is that evidence does suggest that most people probably should be supplementing with Vit D and not doing so for fear of Vit D toxicity is kinda stupid because unless you're taking ridiculous doses for months on end you're realistically never going to reach toxicity levels.
If you're really worried about Vit D toxicity and do not want to do blood testing, please consider just supplementing with 500 - 1,000 IU / daily. Your risk of toxicity at these levels is probably non-existent, but it should ensure at the very least you never become deficient. In my opinion there's really no good reason not to do this, especially if you're at increased risk of having low Vit D (such as being elderly or having a darker skin ton).
Vit D deficiency is such a big problem though that I think it's crazy we don't do more to encourage more people to supplement with it to be honest.
Right? You'd think that we would invest more resources in understanding something that concerns 100% of us in a very profound way (health, maybe even life)
For me, the supplements were noticeable and life changing and I can tell when I have fallen off taking them for a while. But I don't approach anywhere near this dose. Seems like a case of miscommunication.