7 ms·

It's so strange to me that these studies seem to generalize findings (eg results by country) when one of the key biological factors for how we get vitamin D is

It's so strange to me that these studies seem to generalize findings (eg results by country) when one of the key biological factors for how we get vitamin D is skin colour. And at its most basic relationship, the whiter ones' skin, the better one is at generating Vitamin D from sunlight. Perhaps it points to another way in which this disease could disproportionately affect persons of colour? If anyone has any literature that explores it more I'd love some direction.

atourgates 6y ago
I did see that mentioned as a theory a few weeks ago. My best guess is that in the United States especially, it's a combination economic/socitial factors and vitamin D deficiency that's making the virus have higher mortality in populations of racial minorities with darker skin. Here's a study that looked at vitamin D levels and found that they're significantly lower in both people with darker skin, and (independently of skin color) those who are overweight. https://www.jabfm.org/content/29/2/226 https://www.jabfm.org/content/29/2/226
- oneiftwo 6y ago
  > My best guess is that in the United States especially, it's a combination economic/socitial factors and vitamin D deficiency that's making the virus have higher mortality in populations of racial minorities with darker skin African American communities are hardest hit because of genetic and especially cultural practices which predispose them toward obesity, high blood pressure, heart disease, etc. Further, let's not pretend that African American communities have the same level of respect for authority (i.e. following recommendations/orders) as other groups (though to some degree that disdain may be justified, but that's another discussion).
  - dang 6y ago
    If you use HN for race war we will ban you again. No more of this please. Instead, if you'd review https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html and stick to the rules, we'd appreciate it.
- wnmurphy 6y ago
  And the elderly... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782116/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782116/ This is a contributing factor to fractures from falls.
vmception 6y ago
so active people of color in environments with sunlight wouldn't have this effect? like countries closer to the equator
- WaterSponge 6y ago
  accept Ecuador is being particularly ravished by Covid-19 so dont know what that says.
  - elliekelly 6y ago
    I wonder if it says they wear a lot of sunscreen. They’re on the equator and much of the country is at a very high elevation so the sun is particularly strong. When I was in Ecuador for a few months I went through more sunscreen than I had in my whole life up to that point. Without sunscreen I would get burnt to a crisp on an overcast day even when I didn’t spend much time outside.
  - topher515 6y ago
    You made a particularly unfortunate accidental word switch up. I imagine you meant "ravaged". ravished — _fill (someone) with intense delight; enrapture._
    - AnimalMuppet 6y ago
      Captain Nitpick here... That's one definition. It can also mean to carry someone off by force, to kidnap. "Carried away" is the root idea, but it doesn't have to be "by delight".
    - majewsky 6y ago
      Also "accept" is not "except".
  - abiogenesis 6y ago
    Because they are still deficient of vitamin D [1]: > It is evident that, despite the location of Ecuador and the intensity of UV rays it receives throughout the year, Ecuadorian subjects have insufficient levels of vitamin D. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576417/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576417/
kerkeslager 6y ago
> It's so strange to me that these studies seem to generalize findings (eg results by country) when one of the key biological factors for how we get vitamin D is skin colour. They bypass skin color by just measuring levels of Vitamin D directly. This study doesn't care how you got the Vitamin D, it just cares how much you have. There are tons of problems with this study, but failure to look at skin color isn't one of them.
- JumpCrisscross 6y ago
  > They bypass skin color by just measuring levels of Vitamin D directly People with darker skin will, ceteris paribus, have lower vitamin D levels. And all else is not equal.
  - kerkeslager 6y ago
    True, but irrelevant. Even if skin color is a predictor of vitamin D levels, this study doesn't need to predict vitamin D levels because they used measured vitamin D levels.
    - JumpCrisscross 6y ago
      > this study doesn't need to predict vitamin D levels because they used measured vitamin D levels If darker-skinned people have, on average, lower vitamin D levels, then measuring vitamin D levels proxies for skin color. So if the underlying cause is e.g. access to healthcare or stress or exposure to airborne particulates, and those correlate with skin color, those will also correlate with vitamin D levels. One could thus find vitamin D levels relate strongly to outcomes. But increasing vitamin D has zero effect on the outcome. Because it's not the cause. (We see this a lot with poverty correlates in education.)
      - kerkeslager 6y ago
        > If darker-skinned people have, on average, lower vitamin D levels, then measuring vitamin D levels proxies for skin color. "Proxies for" doesn't have a scientific meaning that I'm aware of, so I can't be sure that I understand what you're saying. If what you're saying is that vitamin D levels are correlated with skin color, true, but irrelevant to this study. If what you're saying is that the (poorly substantiated) correlation between Covid19 and vitamin D can be used to claim a correlation between Covid19 and skin color: no, because it's quite possible that vitamin D levels have no effect on Covid19 in people with darker skin, but a huge effect on Covid19 in people with light skin. You also have to keep in mind that your errors multiply across different correlations: the error margin of correlating Covid 19 with skin color via this method is the error margin of correlating Covid19 with vitamin D and the error margi of correlating vitamin D with skin color. If what you're saying is that the (poorly substantiated) correlation between Covid19 and vitamin D can be used to establish a causal relation between Covid 19 and skin color, no, because in addition to the previous problems, you're ignoring that there at least 10 confounding factors besides skin color which also have correlation with vitamin D levels: 1. Latitude 2. How much time you spend outside 3. Which time you spend outside 4. Clothing 5. Sunscreen 6. Liver function 7. Diet 8. Supplementation 9. Cloud cover over time 10. Season If what you're saying is that this study can be used to establish a causal relation between Covid19 and skin color: in addition to all the previous problems, this study can't even really be used to establish a correlation between vitamin D and Covid19, so do we really need to pile on more logical fallacies than are already present?
osazuwa 6y ago
I'm actually pleased it was a study on white folks because since we know that this disease disproportionately kills blacks in the US, and blacks tend to have higher rates of vitamin D deficiency (because of the sunlight/skin pigment issue you mentioned) that we were merely seeing a reflection of the racial imbalance. This study suggests otherwise. That said, there could be other confounding factors. COVID-19 could in fact "drain" vitamin D in some way. We know elderly people are disproportionately killed by the disease, perhaps vitamin D deficiency is more common amongst the elderly. Causal inference from observational data is tricky indeed. That said, vitamin D supplements are cheap (for now). And most people don't get enough anyway. So people should take it.

atourgates 6y ago

I did see that mentioned as a theory a few weeks ago. My best guess is that in the United States especially, it's a combination economic/socitial factors and vitamin D deficiency that's making the virus have higher mortality in populations of racial minorities with darker skin. Here's a study that looked at vitamin D levels and found that they're significantly lower in both people with darker skin, and (independently of skin color) those who are overweight. https://www.jabfm.org/content/29/2/226 https://www.jabfm.org/content/29/2/226

oneiftwo 6y ago
> My best guess is that in the United States especially, it's a combination economic/socitial factors and vitamin D deficiency that's making the virus have higher mortality in populations of racial minorities with darker skin African American communities are hardest hit because of genetic and especially cultural practices which predispose them toward obesity, high blood pressure, heart disease, etc. Further, let's not pretend that African American communities have the same level of respect for authority (i.e. following recommendations/orders) as other groups (though to some degree that disdain may be justified, but that's another discussion).
- dang 6y ago
  If you use HN for race war we will ban you again. No more of this please. Instead, if you'd review https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html and stick to the rules, we'd appreciate it.
wnmurphy 6y ago
And the elderly... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782116/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3782116/ This is a contributing factor to fractures from falls.

vmception 6y ago

so active people of color in environments with sunlight wouldn't have this effect? like countries closer to the equator

WaterSponge 6y ago
accept Ecuador is being particularly ravished by Covid-19 so dont know what that says.
- elliekelly 6y ago
  I wonder if it says they wear a lot of sunscreen. They’re on the equator and much of the country is at a very high elevation so the sun is particularly strong. When I was in Ecuador for a few months I went through more sunscreen than I had in my whole life up to that point. Without sunscreen I would get burnt to a crisp on an overcast day even when I didn’t spend much time outside.
- topher515 6y ago
  You made a particularly unfortunate accidental word switch up. I imagine you meant "ravaged". ravished — _fill (someone) with intense delight; enrapture._
  - AnimalMuppet 6y ago
    Captain Nitpick here... That's one definition. It can also mean to carry someone off by force, to kidnap. "Carried away" is the root idea, but it doesn't have to be "by delight".
  - majewsky 6y ago
    Also "accept" is not "except".
- abiogenesis 6y ago
  Because they are still deficient of vitamin D [1]: > It is evident that, despite the location of Ecuador and the intensity of UV rays it receives throughout the year, Ecuadorian subjects have insufficient levels of vitamin D. [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576417/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576417/

kerkeslager 6y ago

> It's so strange to me that these studies seem to generalize findings (eg results by country) when one of the key biological factors for how we get vitamin D is skin colour. They bypass skin color by just measuring levels of Vitamin D directly. This study doesn't care how you got the Vitamin D, it just cares how much you have. There are tons of problems with this study, but failure to look at skin color isn't one of them.

JumpCrisscross 6y ago
> They bypass skin color by just measuring levels of Vitamin D directly People with darker skin will, ceteris paribus, have lower vitamin D levels. And all else is not equal.
- kerkeslager 6y ago
  True, but irrelevant. Even if skin color is a predictor of vitamin D levels, this study doesn't need to predict vitamin D levels because they used measured vitamin D levels.
  - JumpCrisscross 6y ago
    > this study doesn't need to predict vitamin D levels because they used measured vitamin D levels If darker-skinned people have, on average, lower vitamin D levels, then measuring vitamin D levels proxies for skin color. So if the underlying cause is e.g. access to healthcare or stress or exposure to airborne particulates, and those correlate with skin color, those will also correlate with vitamin D levels. One could thus find vitamin D levels relate strongly to outcomes. But increasing vitamin D has zero effect on the outcome. Because it's not the cause. (We see this a lot with poverty correlates in education.)
    - kerkeslager 6y ago
      > If darker-skinned people have, on average, lower vitamin D levels, then measuring vitamin D levels proxies for skin color. "Proxies for" doesn't have a scientific meaning that I'm aware of, so I can't be sure that I understand what you're saying. If what you're saying is that vitamin D levels are correlated with skin color, true, but irrelevant to this study. If what you're saying is that the (poorly substantiated) correlation between Covid19 and vitamin D can be used to claim a correlation between Covid19 and skin color: no, because it's quite possible that vitamin D levels have no effect on Covid19 in people with darker skin, but a huge effect on Covid19 in people with light skin. You also have to keep in mind that your errors multiply across different correlations: the error margin of correlating Covid 19 with skin color via this method is the error margin of correlating Covid19 with vitamin D and the error margi of correlating vitamin D with skin color. If what you're saying is that the (poorly substantiated) correlation between Covid19 and vitamin D can be used to establish a causal relation between Covid 19 and skin color, no, because in addition to the previous problems, you're ignoring that there at least 10 confounding factors besides skin color which also have correlation with vitamin D levels: 1. Latitude 2. How much time you spend outside 3. Which time you spend outside 4. Clothing 5. Sunscreen 6. Liver function 7. Diet 8. Supplementation 9. Cloud cover over time 10. Season If what you're saying is that this study can be used to establish a causal relation between Covid19 and skin color: in addition to all the previous problems, this study can't even really be used to establish a correlation between vitamin D and Covid19, so do we really need to pile on more logical fallacies than are already present?

osazuwa 6y ago

I'm actually pleased it was a study on white folks because since we know that this disease disproportionately kills blacks in the US, and blacks tend to have higher rates of vitamin D deficiency (because of the sunlight/skin pigment issue you mentioned) that we were merely seeing a reflection of the racial imbalance. This study suggests otherwise. That said, there could be other confounding factors. COVID-19 could in fact "drain" vitamin D in some way. We know elderly people are disproportionately killed by the disease, perhaps vitamin D deficiency is more common amongst the elderly. Causal inference from observational data is tricky indeed. That said, vitamin D supplements are cheap (for now). And most people don't get enough anyway. So people should take it.