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The article wasn’t very detailed and I wasn’t able to figure out if you are more likely to catch COVID because you have a vitamin D deficiency or if catching CO

The article wasn’t very detailed and I wasn’t able to figure out if you are more likely to catch COVID because you have a vitamin D deficiency or if catching COVID causes a vitamin D deficiency. Anyone know?

JohnTHaller 6y ago
From other articles and study abstracts I read, it seems that an existing vitamin D deficiency is correlated with worse Covid-19 outcomes (worse symptoms, higher levels of death).
- SippinLean 6y ago
  This particular study found no causation > No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate component
  - btilly 6y ago
    That doesn't mean what you (and possibly they) think that means. Suppose that characteristic X (eg vitamin D deficiency) puts you at risk of doing worse at Y. If we pick a population based on how poorly they do at Y, we expect to see that X will be more common than it is in the general public. But within that population there is no reason to believe that having characteristic Y makes you do worse - it just made you more likely to do badly enough to be selected. This can be seen quite precisely with a toy model. Suppose that we have a population evenly split between 2 subpopulations with a characteristic that varies on a normal distribution. However one population averages 1 standard deviation worse. If we pick the bottom 5% of the population on that characteristic, we will find about an 80-20 split based on having the risk factor. The bottom 1% also has the same 80-20 split. Ditto the bottom 0.1%, 0.01%, and so on. The reason is that the sum total of how many are in the tail of the normal falls off exponentially fast, with the same exponent in both populations. So the ratio stays constant. No amount of analysis of people in that tail will suggest that characteristic matters. But comparing the population in that tail to the general population, that standard deviation stands out like a sore thumb as a major risk factor. Therefore the fact that about 50% of the general population has vitamin D deficiency while over 80% of those hospitalized with COVID-19 do suggests that vitamin D deficiency is a risk factor. But we should draw no conclusions from the fact that vitamin D deficiency doesn't indicate different outcomes within the population landing in the hospital. (However other research found that patients given vitamin D once landing in the hospital were significantly less likely to wind up in the ICU or dead. We should definitely draw some conclusions from that!)
vmception 6y ago
The paper found no relationship between vitamin d and the severity of the disease To your question, either outcome is enough for you to optimize a diet or activity with adequate amounts of vitamin D because the process is healthier either way unless you were thinking to just try taking supplements
brianwawok 6y ago
The former as there is no known way that Covid reduces vitamin D
- beagle3 6y ago
  Staying home or in a hospital bed without sufficient sunshine exposure (which will likely happen to anyone feeling sick) will reduce vitamin D levels. I don’t know what you consider “known way”, but this Hypothesis is mentioned in almost every discussion, and is not controlled or corrected for in any study I’ve seen. (There is reason to believe vitamin D Supplementation is helpful, based on earlier studies related to viral respiratory diseases - but not yet enough data specifically for covid)
  - smaryjerry 6y ago
    That is false. Get enough vitamin D and it can stay in your system for months. Going to a hospital for a few days will not effect your levels.
zepearl 6y ago
The previous articles I read about Vitamin D & Covid (mentioned in German and Swiss news, not sure about the location of the cases) were related to critical cases in hospitals. Meaning that if the conditions are right (e.g. area having a high virus density, long exposure to low levels, whatever...) you might anyway "catch COVID", but if your vitamin D level is OK then you might be less likely to end up in an hospital or even in intensive care (because by having good vitamin D levels your body can apparently fight better against the virus). I think that none of the stats showed an absolute confirmation of this data. Therefore, in my opinion, your sentence/question is a huge misunderstanding, but of course I might be wrong :)
- dathinab 6y ago
  > but if your vitamin D level is OK then you might be less likely to end up in an hospital or even in intensive care But only as a form of correlation not necessary causation. Which means if you make sure you don't have low vitamin D levels because you heard it is correlated with COVID your likelihood of having worse COVID systems might not change at all! Becau you might have "something" which makes worse COVID systems more likely which also happens to cause low vitamin D levels. Or you might have something caused by your living habits which also makes low vitamin D levels more likely. I.e. as far as I know studies could only find statistic relevance for correlation (in some cases) but no statistic relevance for causation. Idk, but it might literally be as simple as unhealthy older people being more likely to have vitamin D deficit and also being more likely to have worse COVID syntoms.
  - vixen99 6y ago
    If you ignore the extensive literature describing vitamin D's multi-pronged involvement in metabolism then your final sentence is entirely reasonable. Here's a very short summary of some of the effects whereby vitamin D may may be causatively involved in the strongly demonstrated (there are numerous accounts in the literature) inverse relationship between vitamin D levels and the severity of COVID infection. Incidentally the focus should be not on how much vitamin D is taken as a supplement but on the actual blood level. Tons of references on what this should be rather my quoting those levels here. https://www.alliedacademies.org/articles/potential-mechanisms-for-vitamin-d-protective-effect-for-covid19-morbidity-and-mortality.pdf https://www.alliedacademies.org/articles/potential-mechanism...
bhuber 6y ago
I would imagine being in a hospital bed for days without sunlight because you're sick with covid could result in a reduction of vitamin D.
- mrtnmcc 6y ago
  Reasonable.. calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days in the human body.
  - Empact 6y ago
    D3 is also stored in fat, and released as fat is metabolized.
    - deleted 6y ago
      [deleted]
- stjohnswarts 6y ago
  doubtful, the body stores vitamin d in fat cells and individuals that have have sufficient levels will also have some stored up. Vitamin D levels in the blood don't work like an on/off switch depending on how long you were in the sunlight on a specific day or even week.
JshWright 6y ago
You're missing the third option: People who are more likely to be hospitalized due to COVID are also more likely to be deficient in vitamin D. There doesn't have to be a causal relationship at all.
- jb775 6y ago
  I understand what you mean, but don't think your example really fits since an increase in vitamin D in either scenario would ultimately reduce the occurrences of patients showing low vitamin D levels. And this seems to be a fairly consistent finding across multiple studies that use different controls/stratification/etc. Or do you mean people may be becoming deficient in vitamin D as a result of Covid? If so, would be interesting to know their prior vitamin D levels.
  - JshWright 6y ago
    I'm not entirely sure you're replying to the correct comment, but just in case... I mean the population of people who are more likely to be hospitalized due to COVID also happens to be the population of people that is more likely to be deficient in vit D, and neither of those things have to cause the other.
  - deleted 6y ago
    [deleted]
  - rblatz 6y ago
    An increase in Vitamin D levels may or may not impact COVID 19 hospitalization rates. Just like lowering ice cream sales won’t change the murder rate. Even though increased Ice cream sales is correlated with increase murder rate.
    - asveikau 6y ago
      I know your point is that correlation does not mean causation (though maybe those are correlated?), however, that really makes it sound like guys like Ben & Jerry have blood on their hands.
ekanes 6y ago
Since vitamin D is cheap and readily available, we don't need to wait before making sure we have enough of it. Grip strength is another proxy for health, specifically how likely you were to die anytime soon. Makes sense. But training your grip won't make you live longer. Still taking the vitamin D tho...
- emersonrsantos 6y ago
  Are you saying that we can correlate general health to vitamin D levels?
  - nradov 6y ago
    Yes there is some correlation. People who are generally healthy tend to spend more time out in the sun.
  - jokab 6y ago
    Given enough data we can correlate pretty much anything to anything
- adrianN 6y ago
  Have you actually done (or read) a study to show that grip training doesn't increase lifespan?
  - ekanes 6y ago
    I think one would look for a mechanism for how that could work. "How could grip training increase lifespan?" I can't think of a mechanism for that effect, where something else wouldn't be probably better way to spend that effort. Like cardio training.
    - juniper_strong 6y ago
      "Hypertension markedly increases the risk of cardiovascular diseases and overall mortality. Lifestyle modifications, such as increased levels of physical activity, are recommended as the first line of anti-hypertensive treatment. A recent systematic review showed that isometric handgrip (IHG) training was superior to traditional endurance and strength training in lowering resting systolic blood pressure (SBP)" -- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807761/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807761/
colechristensen 6y ago
There is a considerable volume of literature indicating a positive correlation between daily vitamin D supplimentstion and reduced respiratory infections. The quality of the studies isn’t great, but generally a positive impact was found for small doses, especially for children.
wahern 6y ago
AFAIU, catching any illness is likely to reduce your vitamin D levels. For one thing, the active metabolites are created by the liver and then the kidneys. https://www.cdc.gov/nutritionreport/99-02/pdf/nr_ch2b.pdf https://www.cdc.gov/nutritionreport/99-02/pdf/nr_ch2b.pdf Illness can depress this process. See, e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360762/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360762/ Furthermore, if you're bed-ridden then you're not likely getting sunlight, and it only takes a day or two of no sunlight for your serum levels to drop significantly. Of course, none of this is to say that there's no reverse causative relationship as well, but people really need to take these correlation observations with a huge grain of salt. And also take note of extremely inconsistent results when controlled trials are attempted.
vmurthy 6y ago
A slight technicality that I only recently learnt. You catch a virus . In this case it is Sars-CoV-2 . The virus causes a disease. In this case Covid-19. So , how this ladders up (in my understanding at-least is this): People can catch the virus irrespective of Vitamin D levels. The virus can and will replicate in the body. The Vitamin D levels in the body determine the severity of the disease in the said body. This all feels intuitive but I am conscious that immunology is where intuitions go to die so someone please correct me if I am wrong :)
lucas_membrane 6y ago
The studies with positive results are suggesting somewhere around a one binary order of magnitude reduction in risk of infection with possibly some reduction in severity of cases. I'd suspect that the health authorities would not be reluctant to promote a vaccine that had similar results if none better becomes available. Some hospitals are supplementing vitamin D for Covid-19 patients. Trump got it.
- jariel 6y ago
  It is interesting that with this much evidence, public officials are not telling us to take VitD. The masses are crazy though - VitD can be a little dangerous and I can see quite a lot of people taking '10x doses' to get '10x protection' and ending up in the hospital anyhow.
  - lucas_membrane 6y ago
    I saw an article posted someplace a couple of weeks ago telling the story of one person who suffered from too much VitD -- but that person wound up in the hospital only after taking 78000 units/day for about 8 months. That article would have been misleading then if one inferred from it that you really have to seriously knock yourself out to do any damage?
hannob 6y ago
The answer is simple: It's unclear, because the study design they did cannot answer such questions. This is one of the most basic misunderstandings in interpreting scientific studies. If you have "we saw x where we also saw y" then it can mean anything from "x causes y" to "y cause x". And also "unknown factor z causes both x and y", "it's a random coincidence", "they looked into the data long enough with enough different methods to find something" or a combination of all of those.

JohnTHaller 6y ago

From other articles and study abstracts I read, it seems that an existing vitamin D deficiency is correlated with worse Covid-19 outcomes (worse symptoms, higher levels of death).

SippinLean 6y ago
This particular study found no causation > No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate component
- btilly 6y ago
  That doesn't mean what you (and possibly they) think that means. Suppose that characteristic X (eg vitamin D deficiency) puts you at risk of doing worse at Y. If we pick a population based on how poorly they do at Y, we expect to see that X will be more common than it is in the general public. But within that population there is no reason to believe that having characteristic Y makes you do worse - it just made you more likely to do badly enough to be selected. This can be seen quite precisely with a toy model. Suppose that we have a population evenly split between 2 subpopulations with a characteristic that varies on a normal distribution. However one population averages 1 standard deviation worse. If we pick the bottom 5% of the population on that characteristic, we will find about an 80-20 split based on having the risk factor. The bottom 1% also has the same 80-20 split. Ditto the bottom 0.1%, 0.01%, and so on. The reason is that the sum total of how many are in the tail of the normal falls off exponentially fast, with the same exponent in both populations. So the ratio stays constant. No amount of analysis of people in that tail will suggest that characteristic matters. But comparing the population in that tail to the general population, that standard deviation stands out like a sore thumb as a major risk factor. Therefore the fact that about 50% of the general population has vitamin D deficiency while over 80% of those hospitalized with COVID-19 do suggests that vitamin D deficiency is a risk factor. But we should draw no conclusions from the fact that vitamin D deficiency doesn't indicate different outcomes within the population landing in the hospital. (However other research found that patients given vitamin D once landing in the hospital were significantly less likely to wind up in the ICU or dead. We should definitely draw some conclusions from that!)

vmception 6y ago

The paper found no relationship between vitamin d and the severity of the disease To your question, either outcome is enough for you to optimize a diet or activity with adequate amounts of vitamin D because the process is healthier either way unless you were thinking to just try taking supplements

brianwawok 6y ago

The former as there is no known way that Covid reduces vitamin D

beagle3 6y ago
Staying home or in a hospital bed without sufficient sunshine exposure (which will likely happen to anyone feeling sick) will reduce vitamin D levels. I don’t know what you consider “known way”, but this Hypothesis is mentioned in almost every discussion, and is not controlled or corrected for in any study I’ve seen. (There is reason to believe vitamin D Supplementation is helpful, based on earlier studies related to viral respiratory diseases - but not yet enough data specifically for covid)
- smaryjerry 6y ago
  That is false. Get enough vitamin D and it can stay in your system for months. Going to a hospital for a few days will not effect your levels.

zepearl 6y ago

The previous articles I read about Vitamin D & Covid (mentioned in German and Swiss news, not sure about the location of the cases) were related to critical cases in hospitals. Meaning that if the conditions are right (e.g. area having a high virus density, long exposure to low levels, whatever...) you might anyway "catch COVID", but if your vitamin D level is OK then you might be less likely to end up in an hospital or even in intensive care (because by having good vitamin D levels your body can apparently fight better against the virus). I think that none of the stats showed an absolute confirmation of this data. Therefore, in my opinion, your sentence/question is a huge misunderstanding, but of course I might be wrong :)

dathinab 6y ago
> but if your vitamin D level is OK then you might be less likely to end up in an hospital or even in intensive care But only as a form of correlation not necessary causation. Which means if you make sure you don't have low vitamin D levels because you heard it is correlated with COVID your likelihood of having worse COVID systems might not change at all! Becau you might have "something" which makes worse COVID systems more likely which also happens to cause low vitamin D levels. Or you might have something caused by your living habits which also makes low vitamin D levels more likely. I.e. as far as I know studies could only find statistic relevance for correlation (in some cases) but no statistic relevance for causation. Idk, but it might literally be as simple as unhealthy older people being more likely to have vitamin D deficit and also being more likely to have worse COVID syntoms.
- vixen99 6y ago
  If you ignore the extensive literature describing vitamin D's multi-pronged involvement in metabolism then your final sentence is entirely reasonable. Here's a very short summary of some of the effects whereby vitamin D may may be causatively involved in the strongly demonstrated (there are numerous accounts in the literature) inverse relationship between vitamin D levels and the severity of COVID infection. Incidentally the focus should be not on how much vitamin D is taken as a supplement but on the actual blood level. Tons of references on what this should be rather my quoting those levels here. https://www.alliedacademies.org/articles/potential-mechanisms-for-vitamin-d-protective-effect-for-covid19-morbidity-and-mortality.pdf https://www.alliedacademies.org/articles/potential-mechanism...

bhuber 6y ago

I would imagine being in a hospital bed for days without sunlight because you're sick with covid could result in a reduction of vitamin D.

mrtnmcc 6y ago
Reasonable.. calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days in the human body.
- Empact 6y ago
  D3 is also stored in fat, and released as fat is metabolized.
  - deleted 6y ago
    [deleted]
stjohnswarts 6y ago
doubtful, the body stores vitamin d in fat cells and individuals that have have sufficient levels will also have some stored up. Vitamin D levels in the blood don't work like an on/off switch depending on how long you were in the sunlight on a specific day or even week.

JshWright 6y ago

You're missing the third option: People who are more likely to be hospitalized due to COVID are also more likely to be deficient in vitamin D. There doesn't have to be a causal relationship at all.

jb775 6y ago
I understand what you mean, but don't think your example really fits since an increase in vitamin D in either scenario would ultimately reduce the occurrences of patients showing low vitamin D levels. And this seems to be a fairly consistent finding across multiple studies that use different controls/stratification/etc. Or do you mean people may be becoming deficient in vitamin D as a result of Covid? If so, would be interesting to know their prior vitamin D levels.
- JshWright 6y ago
  I'm not entirely sure you're replying to the correct comment, but just in case... I mean the population of people who are more likely to be hospitalized due to COVID also happens to be the population of people that is more likely to be deficient in vit D, and neither of those things have to cause the other.
- deleted 6y ago
  [deleted]
- rblatz 6y ago
  An increase in Vitamin D levels may or may not impact COVID 19 hospitalization rates. Just like lowering ice cream sales won’t change the murder rate. Even though increased Ice cream sales is correlated with increase murder rate.
  - asveikau 6y ago
    I know your point is that correlation does not mean causation (though maybe those are correlated?), however, that really makes it sound like guys like Ben & Jerry have blood on their hands.

ekanes 6y ago

Since vitamin D is cheap and readily available, we don't need to wait before making sure we have enough of it. Grip strength is another proxy for health, specifically how likely you were to die anytime soon. Makes sense. But training your grip won't make you live longer. Still taking the vitamin D tho...

emersonrsantos 6y ago
Are you saying that we can correlate general health to vitamin D levels?
- nradov 6y ago
  Yes there is some correlation. People who are generally healthy tend to spend more time out in the sun.
- jokab 6y ago
  Given enough data we can correlate pretty much anything to anything
adrianN 6y ago
Have you actually done (or read) a study to show that grip training doesn't increase lifespan?
- ekanes 6y ago
  I think one would look for a mechanism for how that could work. "How could grip training increase lifespan?" I can't think of a mechanism for that effect, where something else wouldn't be probably better way to spend that effort. Like cardio training.
  - juniper_strong 6y ago
    "Hypertension markedly increases the risk of cardiovascular diseases and overall mortality. Lifestyle modifications, such as increased levels of physical activity, are recommended as the first line of anti-hypertensive treatment. A recent systematic review showed that isometric handgrip (IHG) training was superior to traditional endurance and strength training in lowering resting systolic blood pressure (SBP)" -- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807761/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5807761/

colechristensen 6y ago

There is a considerable volume of literature indicating a positive correlation between daily vitamin D supplimentstion and reduced respiratory infections. The quality of the studies isn’t great, but generally a positive impact was found for small doses, especially for children.

wahern 6y ago

AFAIU, catching any illness is likely to reduce your vitamin D levels. For one thing, the active metabolites are created by the liver and then the kidneys. https://www.cdc.gov/nutritionreport/99-02/pdf/nr_ch2b.pdf https://www.cdc.gov/nutritionreport/99-02/pdf/nr_ch2b.pdf Illness can depress this process. See, e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360762/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6360762/ Furthermore, if you're bed-ridden then you're not likely getting sunlight, and it only takes a day or two of no sunlight for your serum levels to drop significantly. Of course, none of this is to say that there's no reverse causative relationship as well, but people really need to take these correlation observations with a huge grain of salt. And also take note of extremely inconsistent results when controlled trials are attempted.

vmurthy 6y ago

A slight technicality that I only recently learnt. You catch a virus . In this case it is Sars-CoV-2 . The virus causes a disease. In this case Covid-19. So , how this ladders up (in my understanding at-least is this): People can catch the virus irrespective of Vitamin D levels. The virus can and will replicate in the body. The Vitamin D levels in the body determine the severity of the disease in the said body. This all feels intuitive but I am conscious that immunology is where intuitions go to die so someone please correct me if I am wrong :)

lucas_membrane 6y ago

The studies with positive results are suggesting somewhere around a one binary order of magnitude reduction in risk of infection with possibly some reduction in severity of cases. I'd suspect that the health authorities would not be reluctant to promote a vaccine that had similar results if none better becomes available. Some hospitals are supplementing vitamin D for Covid-19 patients. Trump got it.

jariel 6y ago
It is interesting that with this much evidence, public officials are not telling us to take VitD. The masses are crazy though - VitD can be a little dangerous and I can see quite a lot of people taking '10x doses' to get '10x protection' and ending up in the hospital anyhow.
- lucas_membrane 6y ago
  I saw an article posted someplace a couple of weeks ago telling the story of one person who suffered from too much VitD -- but that person wound up in the hospital only after taking 78000 units/day for about 8 months. That article would have been misleading then if one inferred from it that you really have to seriously knock yourself out to do any damage?

hannob 6y ago

The answer is simple: It's unclear, because the study design they did cannot answer such questions. This is one of the most basic misunderstandings in interpreting scientific studies. If you have "we saw x where we also saw y" then it can mean anything from "x causes y" to "y cause x". And also "unknown factor z causes both x and y", "it's a random coincidence", "they looked into the data long enough with enough different methods to find something" or a combination of all of those.