I've had Vitamin D deficiency from the child and I suffer from Achondroplasia(not diagnosed until recently). I've had ilizarov fixations twice during childhood to fix the bow legs and I had explicit medication for Vitamin -D only when I was teen for couple of years.
But after 15 years, I nearly ended-up becoming a Quadriplegic[1] and I was told my bone condition was like that of 80 year old (I was 32). For the past 2 years I've had single Zoledronic acid injection each year to treat the osteoporosis along with monthly Vitamin D3-Cholecalciferol 60K IU, recent tests showed that there has been about ~ 10% improvement in bone density at some areas and few areas have become worse.
I often wonder if whether I had been put through proper Vitamin D supplement from childhood, the situation would have turned out this bad.
Anyways, Vitamin D seems like the new Yoga and everything from memory to COVID prevention is being attributed to it; but I can say one thing for sure from my experience - If your Vitamin D is low, take proper medication on doctor's advice and follow it up regularly as bone diseases don't come with warning unlike other organs in our body.
No disrespect intended, I am biologically challenged, but I do not understand how anyone can have a Vitamin D deficiency when 15 minutes of sunlight a day on the skin creates all the Vitamin D anyone needs, and too much Vitamin D is very bad. I suppose it makes sense in the Winter months when everyone is inside for months, but usually, the sun shines every day, even in Winter.
If I may add please look into harmala alkaloids specifically harmine to aid in bone density . It is completely unregulated in the USA and the doses required to achieve a proper response isn't high enough to cause nausea or other effects . Dosing twice a day is good enough .
But as always do you own research and read up on contradictions . I recall reading this many years ago because if its effects on DYRK1A
The author explains the following, regarding Vitamin D studies:
> Most studies follow this pattern: Two sets of people are evaluated. One set has a certain disease (diabetes, for example). The other set does not have the disease. Vitamin D levels are measured in both groups. Vitamin D deficiency is found to be much more common in the group of diseased individuals.
If this is true, I wonder if most studies aren’t falling short for failing to control for Vitamin D deficiency. Couldn’t the studies be structured differently?
Let’s say we want to know the effects of Vitamin D on Covid. What if, instead of measuring Vitamin D deficiency in a group with the malady and a group without (analogous to what the author suggests most studies do):
We had two groups made up of Vitamin D deficient people. We gave the first group a Vitamin D supplement and the other a placebo. We then observed both groups out in the wild (ideally a place with a high R), measuring for infections. If the supplement folks were infected at significantly lower rates than placebo folks, wouldn’t this be better at demonstrating causation?
A quasi-fix could be to control for the most obvious sources of vitamin D: how often do you go outside, how long do you go outside, do you take vitamin D supplements, how often and with which strength. You can do this kind of analysis alongside any type of study, don't need full coverage and get some preliminary results. All you need is a Bayesian on your team (: partially in jest) or the willingness to open up your data after you publish.
In my opinion as someone who practices non-medical statistics the trope of correlation vs. causation and interventional vs. observational are somewhat overblown. Andrew Gelman posted somewhat snarky about MDs and statistics recently [1]. I see that this post is in (very) good faith, but it does have the MD-bias to statistics in it.
Do you mean failing to control for the disease causing vitamin D deficiency? Because it seems that's the issue you're addressing with your proposed study design.
Two axis of engineering problem definition not handled by the article are definition of normal and lifestyle variation.
The concept of normal blood chemistry levels is vary vague. Certainly for mariners over 200 years ago the level of vitamin C was always normally very low. Running a nutrition program for Columbus-era mariners to optimize their diet to produce the most numerically average possible vit-C level would be possible but would not be healthy at all. There's a giant subculture of both doctors and average people running all kinds of semi-long term experiments on diet and health. Another side dish is the definition of normal for diet, some consider paleo to be normal diet and some consider twinkies and hot pockets to be normal diet. And of course that "normal" diet interacts in peculiar combination with "normal" concept of blood chemistry making it a very complicated problem.
The lifestyle issue is an interesting problem. Due to local weather I don't go outside and due to exercise hobbies I'm extremely large from weight lifting for many years, also I sweat out a ton of electrolytes and presumably water soluble vitamins every other day. A stereotypical elderly petite sedentary zero-exercise desk worker would likely turn into a pillar of salt if they consumed the same salts I require to prevent muscle cramps, but perhaps this theoretical person is old enough to still falsely consider sun tanning as a healthy activity. Meanwhile our evolutionary ancestors evolved to work as physically hard as me yet do it all out in the sunlight naked. Given this incredible diversity in lifestyle, you'd think we'd all take different vitamin/supplements much like we drink varying amounts of water, perhaps a 5 to 1 ratio of individual variation if not more, but instead the bottle of vit D pills in front of me claims we should all take 125 mcg aka 5000 IU which is 625% of the normal RDA. That seems highly unrealistic.
I'm sure there's potential startup ideas to both gather data and analyze the data. Rather than running a trial on 322 people and hoping its good enough, you could gather less accurate data from 1e6 people, maybe 1e7 people, using some kind of cloudy app statistical sampling thingie.
There's a lot more to this author that the average poster. Deva Boone was commenting in this thread [1], she's a doctor. Seems sensible and makes interesting points. She was posting under https://news.ycombinator.com/user?id=devaboone. Just posting this because there's always kind of wacky things said about the miracle of vitamin D and I was interested in what an actual doc has to say (as opposed to us programmers ;-)).
Interesting that she never mentions the effects of sunlight on Vitamin D levels. I know she has talked about it in other threads on HN, but not in this article.
There was a lot of interest last time on this topic in a previous hacker news discussion [1] so posting this article by my wife (the parathyroid surgeon) here. If you have any questions feel free to post them here and she will check in.
Thanks for sharing. I skimmed the article looking for a specific set of info but may have missed it: how do bodies naturally/organically generate vitamin D and can that be sufficient or are supplements necessary? (E.g. I surf 5 days a week with sunscreen and go for walks regularly. Will I have enough vitamin D or should I supplement?)
Thanks. What are your (or Devas) thoughts on the ritual vitamin company's products (http://ritual.com)? They seem like the most researched multivitamin product I've seen but still never gotten an unbiased opinion!
> Vitamin D is a big deal. Recent studies have shown that patients with low Vitamin D levels are more likely to die from Covid-19 than their Vitamin D-rich counterparts,(1) and deficiency in the vitamin has been linked to seven of the ten leading causes of death in the U.S.(2)
1,500 or so words about Vitamin D, but not a single mention of UV?
Can the correlation between COVID-19 mortality and lack of Vitamin D be explained by lack of exercise and/or exposure to UV?
In other words, maybe Vitamin D levels have nothing to do with the disease. It's just a marker for inactivity, which is the real culprit.
If true, this explanation suggests that pumping people full of Vitamin D in the hope they'll fare better with certain diseases would be about as useful as force-relocating the homeless to Beverly Hills. Correlation, not causation.
The paper cited by the author (1) doesn't consider this possibility, either.
One of the mechanisms proposed in recent years to account for Vit D correlations, but not causations, is that Ultraviolet A (from sun exposure), also helps produce nitric oxide (NB, this is also a very good reason to be a nose breather, as this is a major source of your NO).
This won't account for everything either, but we're now fairly sure that the sun exposure -> VitD -> disease link is not as straight forward, and that VitD supps are not necessarily an answer to the low VitD correlations.
I believe the only VitD supplementation causative link we have strong evidence for is to preventing/treating rickets.
i was reading another thread where people were saying homeless and surfers, people who spend a lot of time outside, often have low vitamin D when they get tested. I have NO idea how true that is, but might be an interesting data point.
I have literally no educational background about any of this, yet this was so well-written that I was able to understand most of it with hardly any cognitive work or re-reading.
This only confirms my belief that informative writing should be written for the least knowledgeable person regardless of the assumed audience, and if anybody thinks you’re stupid for not understanding their informative writing, then that person is a jerk and should learn how to write better.
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.
For a review of many vitamin D studies google "site:theincidentaleconomist.com vitamin d", a blog by a doctor who evaluates many studies. Many do not show extra vitamin D beneficial.
Blog quoute: " The IOM says that anything over 20 ng/mL is “Generally considered adequate for bone and overall health in healthy individuals” and when you get over 50 ng/mL “Emerging evidence links potential adverse effects to such high levels”.
I do not understand why we keep looking for Vitamin D to be some sort of wonder drug. It’s seriously baffling to me."
So we need some,>20ng/ml but keep it under 50 ng/ml.
Correlation may not be causation, but it does provide a null hypothesis to fire at. And people with adequate vitamin D seem to die less (https://www.mayoclinicproceedings.org/article/S0025-6196(18)...). Hence the conclusion in this paper (which does have dosages in it).
"The bottom line is that there is no downside to increasing our intake of vitamin D to maintain serum 25(OH)D at at least 30 ng/mL (75 nmol/L), and preferably at
40–60 ng/mL (100–150 nmol/L) to achieve optimal overall health benefits of vitamin D."
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.
I was pretty excited about vitamin D for cancer prevention. I though it might explain higher cancer prevalence further away from the equator. But then Mendelian randomisation studies showed it made no difference. Having said that there was a large randomised trial (VITAL) with some trends towards reduced cancer burden. Only if BMI was normal however, which is highly salient of itself.
I should wait for the next parts, but I fear the author ignores our very important point of view: we are bayesian machines working with limited information under conditions of bounded rationality.
Lack of proof that Vitamin D supplementation is necessary is irrelevant. We don't work on proofs. If I were to describe our standard, it would a balance of "might it help?" and "might it hurt?". Currently, and I think taking the next parts in consideration as well, I think the answers will be very much in favor of supplementation - with caveats I'm actually very eager to read about.
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.
> Obesity, for example, is a known risk factor for diabetes, and people who are obese also tend to have low Vitamin D levels, due mostly to the dilution of the fat-soluble vitamin in the larger mass of adipose tissue.
I didn't know this. I'm hoping that Part II addresses the long-term Vitamin D storage mechanism. Logically, since sun derived Vitamin D is accumulated during the summer and depleted during the winter, extra storage capacity might be beneficial. This is one area of research where the seasonal cycles are critical. Latitude and the date that samples are collected should be part of the dataset.
Since diet and lifestyle seems to be involved, I wonder how much the phytate [1] content of the starchy staples we consume contributes to Calcium/Magnesium imbalances:
> The (myo) phytate anion is a colorless species that has significant nutritional role as the principal storage form of phosphorus in many plant tissues, especially bran and seeds. It is also present in many legumes, cereals, and grains. Phytic acid and phytate have a strong binding affinity to the dietary minerals, calcium, iron, and zinc, inhibiting their absorption.
It would be ironic if white rice and white bread become recommended over high fiber options. I wonder if the detrimental effects of phytates only apply during digestion, suggesting that some foods shouldn't be mixed in the same meal, or whether the binding affinity is something that occurs in aggregate independent of ingestion time.
A lot of words on correlation != causation without noting any of the causal evidence. Even my 1-pager highlights the obvious responses to this over-used inequality:
1. RCTs show D supplements effective against respiratory infection (Martineau BMJ'17: 25 RCTs, now updated as preprint expanded to ~40RCTs covering ~30,000 people.
2. Causal evidence D is protective against lung injury (in rats) related to ACE2.
3. D extends lifespan in worms (which don't have bones), and we all know how much of a risk factor age is for C19. [This one not in my 1pager, only the full review.]
4. The number of plausible biological mechanism arguments is very large and expanding. See Linda Benskin's excellent review for the most comprehensive review of that evidence up through mid-June. More recently, the active form has been shown to have direct action against SARS-CoV-2.
5. Causal inference model shows that D's effect on C19 is causal [Davies et al].
6. Mendelian randomization shows that the correlations that would need to explain its data are far fetched (eg, systematic racism is worse in the US the farther north you go, by more than 5x) [De Smet et al]
7. Controlled intervention trial shows benefit from D+mag+B12 [Chuen Wen Tan et al]
I don't talk about it in my reviews, but there is also a set of guidelines for when you can infer causation from observational data called Hill's criteria and one paper did apply that to D related data and the evidence so far met all the criteria.
Long pieces that try to create uncertainty around vitamin D in the context of COVID-19 by repeatedly questioning the correlational data without noting any of the relevant causal evidence are far too common these days, and a bit irresponsible at this point.
One "COVID‐19 and Vitamin D" study recommends treatment of COVID‐19 patients with high dose of vitamin D - 200,000 IU of vitamin D2 or vitamin D3 when admitted with COVID-19 followed by 4,000-10,000 IU/day - since populations most vulnerable to COVID-19 are likely vitamin D deficient (https://news.ycombinator.com/item?id=24132440)
Another study (cited by Deva Boone) discusses Vitamin D deficiency is a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19: 81% of patients had hypovitaminosis D; severe vitamin D deficiency patients had a 50% mortality probability, while those with vitamin D ≥ 10 ng/mL had a 5% mortality risk (https://news.ycombinator.com/item?id=24109396)
Vitamin D deficiency is more or less inversely proportional to the amount of time one spends active and outside, isn't it?
I'm sure this has been answered somewhere on the internet, but wouldn't it be reasonable to posit that a sedentary lifestyle is likely the root cause of many of these health issues correlated with vitamin D deficiency?
> In a study of Hawaiian surfers with sun exposure of at least 15 hours per week for the preceding 3 months, 25(OH)D levels ranged from 11 up to 71 ng/mL, demonstrating wide individual variation.
Hopefully part 2 will contain a section about how Vitamin D regulates cytokine production in your lungs. Without enough vitamin d, your body over reacts to a respiratory illness by over producing cytokines, and then the patient has a much higher chance of dying.
There has to be additional evidence showing a decline in vitamin D levels over the past 20 years or so as we all got addicted to our devices, became narcissistic and anti social as a result of social media addiction, and largely stayed inside more than we used to. So we cut off our main source of vitamin D over time, and here we are...
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.
[+] [-] Abishek_Muthian|5 years ago|reply
But after 15 years, I nearly ended-up becoming a Quadriplegic[1] and I was told my bone condition was like that of 80 year old (I was 32). For the past 2 years I've had single Zoledronic acid injection each year to treat the osteoporosis along with monthly Vitamin D3-Cholecalciferol 60K IU, recent tests showed that there has been about ~ 10% improvement in bone density at some areas and few areas have become worse.
I often wonder if whether I had been put through proper Vitamin D supplement from childhood, the situation would have turned out this bad.
Anyways, Vitamin D seems like the new Yoga and everything from memory to COVID prevention is being attributed to it; but I can say one thing for sure from my experience - If your Vitamin D is low, take proper medication on doctor's advice and follow it up regularly as bone diseases don't come with warning unlike other organs in our body.
[1]https://abishekmuthian.com/i-was-told-i-would-become-quadrip...
[+] [-] catmistake|5 years ago|reply
No disrespect intended, I am biologically challenged, but I do not understand how anyone can have a Vitamin D deficiency when 15 minutes of sunlight a day on the skin creates all the Vitamin D anyone needs, and too much Vitamin D is very bad. I suppose it makes sense in the Winter months when everyone is inside for months, but usually, the sun shines every day, even in Winter.
[+] [-] costcopizza|5 years ago|reply
[+] [-] jokowueu|5 years ago|reply
But as always do you own research and read up on contradictions . I recall reading this many years ago because if its effects on DYRK1A
[+] [-] amgreg|5 years ago|reply
> Most studies follow this pattern: Two sets of people are evaluated. One set has a certain disease (diabetes, for example). The other set does not have the disease. Vitamin D levels are measured in both groups. Vitamin D deficiency is found to be much more common in the group of diseased individuals.
If this is true, I wonder if most studies aren’t falling short for failing to control for Vitamin D deficiency. Couldn’t the studies be structured differently?
Let’s say we want to know the effects of Vitamin D on Covid. What if, instead of measuring Vitamin D deficiency in a group with the malady and a group without (analogous to what the author suggests most studies do):
We had two groups made up of Vitamin D deficient people. We gave the first group a Vitamin D supplement and the other a placebo. We then observed both groups out in the wild (ideally a place with a high R), measuring for infections. If the supplement folks were infected at significantly lower rates than placebo folks, wouldn’t this be better at demonstrating causation?
[+] [-] wjnc|5 years ago|reply
In my opinion as someone who practices non-medical statistics the trope of correlation vs. causation and interventional vs. observational are somewhat overblown. Andrew Gelman posted somewhat snarky about MDs and statistics recently [1]. I see that this post is in (very) good faith, but it does have the MD-bias to statistics in it.
[1] https://statmodeling.stat.columbia.edu/2020/08/11/that-not-a...
[+] [-] mft_|5 years ago|reply
Such Interventional studies can be done, but would be more difficult and expensive, and might be difficult to get an answer from.
[+] [-] choxi|5 years ago|reply
[+] [-] jwally|5 years ago|reply
Maybe its just acting as a first-filter of things to (not) investigate at more expense later?
Otherwise you'd get a ton of studies promoting solutions as cause-and-effect when they're only coincidentally related:
- U.S. Spending on science correlates @99.8% with suicide by hanging
- Drownings correlates with Nic Cage films @66%
- Japanese passenger cars sold in US correlates with suicide by motor-vehicle @ 93.57%
*source: https://tylervigen.com/spurious-correlations
[+] [-] jonny_eh|5 years ago|reply
Do you mean failing to control for the disease causing vitamin D deficiency? Because it seems that's the issue you're addressing with your proposed study design.
[+] [-] VLM|5 years ago|reply
https://pubmed.ncbi.nlm.nih.gov/23032549/
As a very general example I think you'd have a lot of fun looking at examine.com pages that link to medical studies.
https://examine.com/supplements/vitamin-d/
Two axis of engineering problem definition not handled by the article are definition of normal and lifestyle variation.
The concept of normal blood chemistry levels is vary vague. Certainly for mariners over 200 years ago the level of vitamin C was always normally very low. Running a nutrition program for Columbus-era mariners to optimize their diet to produce the most numerically average possible vit-C level would be possible but would not be healthy at all. There's a giant subculture of both doctors and average people running all kinds of semi-long term experiments on diet and health. Another side dish is the definition of normal for diet, some consider paleo to be normal diet and some consider twinkies and hot pockets to be normal diet. And of course that "normal" diet interacts in peculiar combination with "normal" concept of blood chemistry making it a very complicated problem.
The lifestyle issue is an interesting problem. Due to local weather I don't go outside and due to exercise hobbies I'm extremely large from weight lifting for many years, also I sweat out a ton of electrolytes and presumably water soluble vitamins every other day. A stereotypical elderly petite sedentary zero-exercise desk worker would likely turn into a pillar of salt if they consumed the same salts I require to prevent muscle cramps, but perhaps this theoretical person is old enough to still falsely consider sun tanning as a healthy activity. Meanwhile our evolutionary ancestors evolved to work as physically hard as me yet do it all out in the sunlight naked. Given this incredible diversity in lifestyle, you'd think we'd all take different vitamin/supplements much like we drink varying amounts of water, perhaps a 5 to 1 ratio of individual variation if not more, but instead the bottle of vit D pills in front of me claims we should all take 125 mcg aka 5000 IU which is 625% of the normal RDA. That seems highly unrealistic.
I'm sure there's potential startup ideas to both gather data and analyze the data. Rather than running a trial on 322 people and hoping its good enough, you could gather less accurate data from 1e6 people, maybe 1e7 people, using some kind of cloudy app statistical sampling thingie.
[+] [-] unknown|5 years ago|reply
[deleted]
[+] [-] pdr2020|5 years ago|reply
[deleted]
[+] [-] nick_kline|5 years ago|reply
1. https://news.ycombinator.com/item?id=24061164 Vitamin D and covid-19 mortality.
[+] [-] wyclif|5 years ago|reply
[+] [-] conorh|5 years ago|reply
[1] https://news.ycombinator.com/item?id=24061164
[+] [-] dilippkumar|5 years ago|reply
I'd love to read more posts in the future, but it's very unlikely that I'll come to devaboone.com every day to look for new posts.
Can you please set up an RSS feed?
[+] [-] bdickason|5 years ago|reply
[+] [-] ramraj07|5 years ago|reply
[+] [-] aazaa|5 years ago|reply
1,500 or so words about Vitamin D, but not a single mention of UV?
Can the correlation between COVID-19 mortality and lack of Vitamin D be explained by lack of exercise and/or exposure to UV?
In other words, maybe Vitamin D levels have nothing to do with the disease. It's just a marker for inactivity, which is the real culprit.
If true, this explanation suggests that pumping people full of Vitamin D in the hope they'll fare better with certain diseases would be about as useful as force-relocating the homeless to Beverly Hills. Correlation, not causation.
The paper cited by the author (1) doesn't consider this possibility, either.
[+] [-] mellosouls|5 years ago|reply
Using this study method, Vitamin D deficiency is correlated with many diseases. But correlation does not equal causation.
[+] [-] Quarrel|5 years ago|reply
This won't account for everything either, but we're now fairly sure that the sun exposure -> VitD -> disease link is not as straight forward, and that VitD supps are not necessarily an answer to the low VitD correlations.
I believe the only VitD supplementation causative link we have strong evidence for is to preventing/treating rickets.
[+] [-] throwawaye3735|5 years ago|reply
[+] [-] drited|5 years ago|reply
[+] [-] greenie_beans|5 years ago|reply
This only confirms my belief that informative writing should be written for the least knowledgeable person regardless of the assumed audience, and if anybody thinks you’re stupid for not understanding their informative writing, then that person is a jerk and should learn how to write better.
[+] [-] devaboone|5 years ago|reply
[+] [-] ibigb|5 years ago|reply
Blog quoute: " The IOM says that anything over 20 ng/mL is “Generally considered adequate for bone and overall health in healthy individuals” and when you get over 50 ng/mL “Emerging evidence links potential adverse effects to such high levels”. I do not understand why we keep looking for Vitamin D to be some sort of wonder drug. It’s seriously baffling to me."
So we need some,>20ng/ml but keep it under 50 ng/ml.
[+] [-] wtetzner|5 years ago|reply
[+] [-] neilwilson|5 years ago|reply
https://www.mdpi.com/2072-6643/12/7/2097/htm
"The bottom line is that there is no downside to increasing our intake of vitamin D to maintain serum 25(OH)D at at least 30 ng/mL (75 nmol/L), and preferably at 40–60 ng/mL (100–150 nmol/L) to achieve optimal overall health benefits of vitamin D."
[+] [-] devaboone|5 years ago|reply
[+] [-] jjt-yn_t|5 years ago|reply
[deleted]
[+] [-] Gatsky|5 years ago|reply
[+] [-] manmal|5 years ago|reply
There are thousands of papers on the positive effects of photobiomodulation (exposure to visible and near infrared photons): https://docs.google.com/spreadsheets/d/1ZKl5Me4XwPj4YgJCBes3...
[+] [-] simonebrunozzi|5 years ago|reply
I wish more people would write like this.
[+] [-] devaboone|5 years ago|reply
[+] [-] radu_floricica|5 years ago|reply
Lack of proof that Vitamin D supplementation is necessary is irrelevant. We don't work on proofs. If I were to describe our standard, it would a balance of "might it help?" and "might it hurt?". Currently, and I think taking the next parts in consideration as well, I think the answers will be very much in favor of supplementation - with caveats I'm actually very eager to read about.
[+] [-] devaboone|5 years ago|reply
[+] [-] electriclove|5 years ago|reply
How can I find out if I am deficient in Vitamin D? Can I do this without an office visit or lab visit?
How much should I supplement with?
[+] [-] sradman|5 years ago|reply
I didn't know this. I'm hoping that Part II addresses the long-term Vitamin D storage mechanism. Logically, since sun derived Vitamin D is accumulated during the summer and depleted during the winter, extra storage capacity might be beneficial. This is one area of research where the seasonal cycles are critical. Latitude and the date that samples are collected should be part of the dataset.
Since diet and lifestyle seems to be involved, I wonder how much the phytate [1] content of the starchy staples we consume contributes to Calcium/Magnesium imbalances:
> The (myo) phytate anion is a colorless species that has significant nutritional role as the principal storage form of phosphorus in many plant tissues, especially bran and seeds. It is also present in many legumes, cereals, and grains. Phytic acid and phytate have a strong binding affinity to the dietary minerals, calcium, iron, and zinc, inhibiting their absorption.
It would be ironic if white rice and white bread become recommended over high fiber options. I wonder if the detrimental effects of phytates only apply during digestion, suggesting that some foods shouldn't be mixed in the same meal, or whether the binding affinity is something that occurs in aggregate independent of ingestion time.
[1] https://en.wikipedia.org/wiki/Phytic_acid
[+] [-] charlieflowers|5 years ago|reply
[+] [-] kpfleger|5 years ago|reply
A lot of words on correlation != causation without noting any of the causal evidence. Even my 1-pager highlights the obvious responses to this over-used inequality:
1. RCTs show D supplements effective against respiratory infection (Martineau BMJ'17: 25 RCTs, now updated as preprint expanded to ~40RCTs covering ~30,000 people.
2. Causal evidence D is protective against lung injury (in rats) related to ACE2.
3. D extends lifespan in worms (which don't have bones), and we all know how much of a risk factor age is for C19. [This one not in my 1pager, only the full review.]
4. The number of plausible biological mechanism arguments is very large and expanding. See Linda Benskin's excellent review for the most comprehensive review of that evidence up through mid-June. More recently, the active form has been shown to have direct action against SARS-CoV-2.
5. Causal inference model shows that D's effect on C19 is causal [Davies et al].
6. Mendelian randomization shows that the correlations that would need to explain its data are far fetched (eg, systematic racism is worse in the US the farther north you go, by more than 5x) [De Smet et al]
7. Controlled intervention trial shows benefit from D+mag+B12 [Chuen Wen Tan et al]
I don't talk about it in my reviews, but there is also a set of guidelines for when you can infer causation from observational data called Hill's criteria and one paper did apply that to D related data and the evidence so far met all the criteria.
Long pieces that try to create uncertainty around vitamin D in the context of COVID-19 by repeatedly questioning the correlational data without noting any of the relevant causal evidence are far too common these days, and a bit irresponsible at this point.
Karl
[+] [-] kpfleger|5 years ago|reply
[+] [-] InInteraction|5 years ago|reply
One "COVID‐19 and Vitamin D" study recommends treatment of COVID‐19 patients with high dose of vitamin D - 200,000 IU of vitamin D2 or vitamin D3 when admitted with COVID-19 followed by 4,000-10,000 IU/day - since populations most vulnerable to COVID-19 are likely vitamin D deficient (https://news.ycombinator.com/item?id=24132440)
Another study (cited by Deva Boone) discusses Vitamin D deficiency is a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19: 81% of patients had hypovitaminosis D; severe vitamin D deficiency patients had a 50% mortality probability, while those with vitamin D ≥ 10 ng/mL had a 5% mortality risk (https://news.ycombinator.com/item?id=24109396)
[+] [-] hellofunk|5 years ago|reply
[+] [-] toomanybeersies|5 years ago|reply
I'm sure this has been answered somewhere on the internet, but wouldn't it be reasonable to posit that a sedentary lifestyle is likely the root cause of many of these health issues correlated with vitamin D deficiency?
[+] [-] WalterSear|5 years ago|reply
https://pubmed.ncbi.nlm.nih.gov/17218096/
> In a study of Hawaiian surfers with sun exposure of at least 15 hours per week for the preceding 3 months, 25(OH)D levels ranged from 11 up to 71 ng/mL, demonstrating wide individual variation.
[+] [-] kkaranth|5 years ago|reply
[+] [-] astura|5 years ago|reply
[+] [-] Threeve303|5 years ago|reply
There has to be additional evidence showing a decline in vitamin D levels over the past 20 years or so as we all got addicted to our devices, became narcissistic and anti social as a result of social media addiction, and largely stayed inside more than we used to. So we cut off our main source of vitamin D over time, and here we are...
[+] [-] devaboone|5 years ago|reply