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).
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.