Thanks! It is very helpful. These are great points. I actually tell my patients that every supplement or vitamin should be thought of as a medication. I had written "should be thought of" in the article and then just switched to "is a medication" to make the sentence simpler. It probably changed the meaning too much. It's been very interesting to read the responses on here, and I appreciate the feedback.
This is really interesting. I usually do not use anecdotes, but chose this to make one simple point. The point was not what you got from it, though, which means I failed in my messaging. The point was not to shift a definition (Vitamin D is a steroid hormone, and by definition Vitamin D is NOT in fact a vitamin). The point was that I would like people to think of Vitamin D as a medication, not a dietary supplement. I think when you frame it as a medication, people treat it differently. That was the whole point of the post. In the next post, I will go back to being completely scientific, which is my normal state.
Agree. It's nice to say that I did something and the patient had amazing results, but it doesn't mean that my action had anything to do with how they felt. Many people will recover from the flu without any treatment. It might not matter whether you give a vitamin.
Thanks for commenting. These are all great points. For a while I have thought that Vitamin D just became the latest Vitamin C - are people on here old enough to remember when Vitamin C was a miracle drug that treated and prevented cancer? Fortunately you can expel excess Vitamin C much easier than Vitamin D. In my next post on this I really want to go into the human trials. The evidence for Vitamin D supplementation in the general population is just not there. And yes, darker skin color is a risk for Vitamin D deficiency. And the correlations that you mention are all real, which can partly explain the correlations between low Vitamin D and health problems - and then explain why supplementing doesn't seem to help. It's not the Vitamin D causing an increased mortality - it's everything else that might be associated with low Vitamin D and at the same time associated with mortality.
I'm the one who wrote the article. I would actually argue that the risk of low Vitamin D has been overplayed. There are very alarmist articles out there about this epidemic of Vitamin D deficiency - which causes people to go out and buy supplements. But there is very little actual data showing that healthy people should take Vitamin D. This is where you get into the large human trials of Vitamin D supplementation, which I want to get into for part 3.
I'm the physician who wrote the article. And I agree with you. Vitamin D deficiency is a problem because it leads to bone loss (see part 1: https://www.devaboone.com/post/vitamin-d-part-1-back-to-basi...). And Vitamin D supplements can be very helpful for those with a deficiency. The point that I am trying to make is that Vitamin D should not be thought of as a dietary supplement. I am seeing more and more people with high calcium levels from being on high-dose Vitamin D. If you treat Vitamin D like the steroid hormone that it is, you will treat it like a medicine, and not take outrageous doses because someone online suggested it. At least, that's what I'm trying to get across.
This is a great point. Vitamin D deficiency causes problems, and should be treated. 5000 units a day can be great for treating a deficiency - until you are no longer deficient. The answer for you is checking your Vitamin D 25-OH level. If it is still low (under around 30), then you may need the high dose. If it is getting too high (above 60) then you need to back off. There isn't a one-size-fits-all dose for everyone.
Vitamin K2 is definitely an essential vitamin for bone health and calcium regulation, but it won't counteract high dose Vitamin D. If you are on so much Vitamin D that your calcium is elevated (meaning, you are at a toxic dose of Vitamin D), Vitamin K2 is not going to help. The best thing to do is actually check your Vitamin D levels if you are planning on staying on high dose Vitamin D.
Unfortunately there are a lot of places online that will recommend 5000 units a day or more. And at the store, one of the standard doses for Vit D is 5000 units. I have this dose in my medicine cabinet. And it's not a completely unreasonable dose. Shannon actually did need 5000 units daily - just not for five years. The problem is that no one knew to reconsider it, or look for elevated calcium.
Thanks for commenting! I wrote the blog, and I like your point of view. There was only so much I could cover in one post, but I do hope to get to these issues. And you are right, for most people the conclusion will likely be that a moderate dose of Vitamin D is not likely to harm, and may help - but then there are many many arguments over what constitutes a moderate dose, and I hope to cover that as well.
This is a good point. And I do want to get to more of the studies done in humans. Although I haven't discussed dosages yet, my advice on everything in life is pretty much: everything in moderation.
Cytokine production wasn't something I was able to include, simply because I was trying to cover a lot of ground in 1200 words! I alluded to it in the discussion about the cascade of events that occur when Vitamin D binds to immune cells. Cytokine production is one of those events. Still, I'm not completely convinced that Vitamin D deficiency directly leads to a higher chance of dying due to cytokine production. It's another one of those areas where we have a correlation, and a plausible explanation for causation... but it's not straightforward.
And yes, the lack of sunlight is one explanation for why we seem to have so much Vitamin D deficiency... then again, maybe we see so much because we are defining deficiency the wrong way. There are so many things to discuss, and hopefully I can get to all of them.
Thank you! I wrote the blog post, and my goal was to make it so that someone without any medical background could understand it. By the time I finished, I wasn't sure if I had accomplished that. The article is still pretty dense with medical science. So glad you commented.
Hi, I'm the one who wrote the blog post. Thanks for commenting. Sunlight is important. There are a lot of things that are also important that aren't in the blog, simply because I couldn't cover all of them and keep the post to a manageable size. I like reading these comments to find out what people want to know, though, and what I should cover in the next post. Sunlight will be addressed.
I'm the one who wrote the blog, and really appreciate your comment. As a physician, I can confirm that most physicians have only the tiniest grasp on statistics - and most will not have even heard about Bayesian stats.
I do not want to imply that observational studies of correlation are useless - or even that observational studies are "less valid" than randomized controlled trials (something that doctors usually assume, but it incorrect). I actually want to write about this issue in future posts. There is a lot I want to cover, and stats in medicine is one of my favorite topics. One blog at a time, though.
I love this Spurious Correlations site. And you are correct - a correlation can be a first-filter, especially if you have some reason to believe that there would be a causative connection. And though "correlation does not equal causation" is a cliche, it is still so easy to get sucked into equating the two. Part of the human brain's desire to make sense of things.
Great point. Low Vitamin D is common in very sick people, partly because they are not as active, not going outside, and may not be eating the best diets. There are trials like you describe, which I'm hoping to get to in part 2... or 3? There is a ton of information to cover!
It is difficult to die of a Vitamin D overdose, though not impossible. Here is what happens: Vitamin D increases calcium absorption from the intestines. Over time, if you are taking too much Vitamin D, your levels can get very very high over time. Vitamin D is fat soluble, so you don't just "pee it out" like some water-soluble vitamins. It stays in you long-term. Eventually your calcium will rise. It can rise slowly, but you will get symptoms. Common symptoms would be fatigue, brain fog, insomnia, headaches, and kidney stones.
If you are at levels where you could potentially die from Vitamin D overdose, your calcium levels will be high enough that you will feel acute symptoms of markedly elevated calcium: like vomiting and confusion. Someone will end up taking you to the hospital, because you will become unconscious. At that point you will be given IV fluids and the calcium will drop. You could die, especially if you have other health issues, but more likely it would be treated and you would get released.
The effects of Vitamin D toxicity are related to the high calcium levels that it causes.
Correct. It's fairly easy to know whether the dosage you are taking is working, since you can check levels. 8000 units is a really high dose, one that I have never had to give. The article suggests that 98% of people require that much to get to normal levels, which is almost laughable.
I do see people get high calcium levels after being on this dose for years. But not always. You may be able to handle that dose. If you are getting "routine" labs done, then there is likely a calcium level in there. If your calcium is normal (under 10.0 mg/dl for adults over 40, younger adults can be a little higher), then your Vitamin D dose is ok... but I would still recommend coming down a bit on that dose. It is a high dose, and Vit D builds up in your body, since it is a fat soluble vitamin.
5000 IU is high dose. 10,000 is really high. A more moderate dose would be 1000 to 2000 daily.
If you live in a northern state, your Vitamin D level will vary with season. And with increased use of sunscreen (which is a good thing), it can be hard to get enough Vitamin D. I'm not opposed to anyone taking Vitamin D (I take it actually). I just want people to take it in moderation unless there is a very clear reason for taking high doses (and there are indications for that).
Some people can tolerate Vitamin D levels above 50, so I wouldn't set that as an absolute cutoff - a Vitamin D in the 50s is good for many people, but I definitely don't want to see it above 70. Taking a higher dose for a short period of time is completely acceptable, as long as it doesn't become something that you stay on for years. It is really hard, if not impossible, to get toxic levels of Vitamin D solely from the sun or diet. I only see it with people taking supplements. And usually it's not a low dose of supplements. (And actually, many people don't even realize that they are getting high doses of Vitamin D. It is added to a lot of vitamins and supplements - so that supplement you take for hair growth may contain a few thousand units of Vitamin D, for example. I ask everyone to get out all of their supplements and look through for vitamin D.) In general, getting vitamins and minerals from diet is preferable to getting from supplements.
No, it doesn't. I haven't had a chance to really critically review the studies that are cited in that article, so I can't give an in-depth answer as to why that article is wrong. But I know that my recommendations are based on patients I have treated. And I have treated thousands of patients with parathyroid, calcium, and Vitamin D problems. That is all that I have done for the last 6 years, in fact. I've never had a patient require 8000 units of Vit D daily to get to a normal level - never. Yet this article would have me believe that 98% of people require over 8000 units to get Vit D in the normal range?! That is absurd. Anyone who has prescribed Vitamin D and watched levels knows that this isn't true. Many things published in medical literature are not valid, and not reproducible.
Vitamin K2 does help bones absorb calcium, but it will not prevent the blood calcium level from rising if you are really taking more Vitamin D than you need. This is simply wishful thinking.
Calcium supplements often include Vitamin D because it aids in intestinal absorption of calcium. That is actually one of the main roles of Vitamin D. You can find Vitamin D by itself, in anywhere from 400 to 5000 units per pill.
Taking high doses of Vitamin D can cause high calcium (due to more being absorbed in the intestines), and taking extra calcium would just exacerbate that. If someone has low calcium levels, I recommend taking both calcium and Vitamin D. Low Vitamin D can cause low calcium levels.
I read the study that is cited on your link. It was a review article about Vitamin D, not a study on Vitamin D toxicity. And in fact, in the references for that article, there is no study cited directly related to Vitamin D toxicity that I can see. The cutoff at 10K is largely someone's opinion. I cannot say how many people will be harmed by taking such a high dose, but I know with certainty that toxicity at that dose is not rare, because I see it all the time. Some people can take very high doses and be just fine, calcium stays normal. Others will take 5000 units daily and end up with high calcium, and all the symptoms that go along with that (including kidney stones, fatigue, cardiac arrhythmias, etc). Now I am not saying that NO ONE should take high dose Vit D. Some people actually need that high dose, but that is only in the case of someone with very low Vit D and low calcium levels - often in someone who has problems with intestinal absorption, as you would see in someone who had a gastric bypass, for example.
There are some very vocal people who argue that the risk of toxicity is very low. The studies aren't great. But for most people, taking a moderate dose of Vitamin D will be safe.
Unfortunately, I have treated many patients who come to me with high calcium levels due to taking Vitamin D. They do not have parathyroid disease (I have treated thousands of patients with parathyroid disease). They have simply been taking high doses of Vitamin D. High dose is generally 5000 units a day or more, though I have seen it occur with lower doses if taken over many years. Vitamin D is fat soluble, so it will stay in your system for a long time, building up.
Of note, some of those patients were instructed by their doctors to take those high doses. Even doctors forget the relationship between calcium and Vitamin D, and I have spoken with doctors who did not realize that 5000 units a day could cause problems. As a doctor, there is a lot to know and remember, and most doctors haven't studied calcium metabolism in many years.
Calcium metabolism is complicated, but there are a few things that are straightforward.
1. Vitamin D helps the intestines absorb calcium, so taking more Vitamin D can lead to more calcium being absorbed in your intestines, and thus more calcium in the blood. The excess calcium in your blood is caused by increased absorption from the intestines, not from bone release. (High calcium with parathyroid disease is caused by bone release, as well as increased intestinal absorption)
2. Taking calcium supplements along with Vitamin D will allow your intestines to absorb more of the calcium you are taking.
3. There are several reasons for having a lot of calcium in the urine. Primary hyperparathyroidism can do it, and in this case you will see high blood calcium levels also. If the blood calcium is low or normal (under 10.0 mg/dl), then you have another reason for high urine calcium.
Hi, I'm the wife. High dose Vitamin D can cause elevated calcium levels (meaning over 10.0 mg/dl for adults over 40, it can be a little higher for younger adults). I usually don't see that occur with doses at 2-3 K IU daily. You can also check your Vitamin D 25-OH levels (the level that will be done if you just get a standard "Vitamin D level") and these should be in a reasonable range. What constitutes reasonable may be debatable, but in general I do not see elevated calcium levels with Vitamin D levels that are under 50 ng/ml (unless the person has parathyroid disease, another topic). The "toxic" range for Vitamin D is usually set to 100, but this is well over where most people should be. Toxicity with regard to Vitamin D means high calcium - that is the toxic effect. And I have seen this toxic effect occur with Vit D levels in the 50s.