7 ms·

> Vitamin D naturally occurs when people go outside and get exposed to the sun, ... Not sure where you are living? If I go outside in winter (+2 months around)

> Vitamin D naturally occurs when people go outside and get exposed to the sun, ... Not sure where you are living? If I go outside in winter (+2 months around) I need gloves, cap, scarf. Literally only a little portion of my face gets some sunlight until 5pm. Then it is dark! I live in Germany! So, this isn't an argument for a lot of people in cold countries or dark countries. Mostly both.. Exposing to the sun is very hard here around the year.

napierzaza 4y ago
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tedunangst 4y ago
It's hard to find good answers on actual timelines, but vitamin D is fat soluble and you don't become insufficient after just a week of sitting in the dark.
- freeone3000 4y ago
  More like six months.
- Aldipower 4y ago
  I am talking about months of actual lack of sunlight, not a week. I for myself know 2 friends which diagnosed with vitamin D insufficiency. Because we are relatively young this lead to bone problems while doing sports. Without sports it wouldn't be recognized.
  - neffo 4y ago
    Interestingly, this was a bit over-diagnosed maybe 10ish years ago. Not saying this was the case, but some doctors were ordering VitD tests, getting results that said below average or below normal and interpreting it as insufficiency.
- crazygringo 4y ago
  You sure do by February or March though, if the last time you spent an afternoon at the park (or the beach) was late August.
version_five 4y ago
I had thought that it was possible to get vitamin D from moderate sun exposure in the winter and went looking for info to refute your post. Turns out you are right and I was wrong: https://www.nytimes.com/2022/12/06/well/live/vitamin-d-deficiency-winter.html https://www.nytimes.com/2022/12/06/well/live/vitamin-d-defic... People living above the 37th parallel, basically the tropics, may not be getting enough in the winter, because the sun isn't strong enough to provide it.
- adriand 4y ago
  It’s brutal, I live near Toronto and not only is the winter sun quite weak but sunny days are quite uncommon. Almost every day is grey and overcast. Combine that with short daylight periods and winter becomes quite the gruelling challenge in terms of mental health especially.
  - tharkun__ 4y ago
    Weeeellll :) Toronto Harborfront Center is at 43.6397877,-79.3836877,17.12z according to Google. If I look for the southern most part of Germany, that seems to be Oberstdorf which is at 47.3997083,10.2805651,14.08z ;) Or in other words, Germany in terms of natural sun light exposure in winter is way worse than Toronto. In fact, in Germany its dark much earlier and sun comes up much later for longer. I hear cloud cover is very comparable to the Toronto weather you describe so aptly. One of the most populated areas of Germany is at around 51.5, if we wanted to "guess" where aldipower might be from. Going mostly straight up from Toronto, if you want to hit "civilization" at that level, that's Waskaganish, QC or Moosonee, ON a bit more south, right on our beautiful Hudson Bay. I complain less and less about our beautiful country, the more I compare it w/ the world ;)
    - adriand 4y ago
      Wow, TIL. That’s kind of nuts, I just looked at latitude lines because I was sure you had to be wrong but it looks like where I live (which is actually Hamilton) is the same latitude as northern Italy. In fact, it’s almost exactly the same as Florence, where the forecasted highs over the next week are in mid- to high-teens (C). We have a blizzard and most days next week the high is 1 degree. I honestly didn’t realize how much climate is not strictly determined by latitude!
fshbbdssbbgdd 4y ago
Even if there is no sunlight for half the year (and this completely equalizes vitamin D levels in winter), various confounders of sun exposure will still affect a study on vitamin D levels, assuming the study collects some samples during the period when there is sunlight and vitamin D levels vary. Also, the confounders of vitamin D supplementation I mentioned would apply even if you never get exposed to the sun. I think your comment is assuming the vitamin D supplementation is effective, when that hasn’t really been established. We don’t even know that vitamin D has a direct effect on most of the correlated health measures.
_yb2s 4y ago
Our bodies can store enough to make it through the winter if you are replete at the beginning.
- iopq 4y ago
  That, of course, assumes you don't wear sunscreen during the summer/fall, which I do
  - codethief 4y ago
    You might enjoy this article: https://www.outsideonline.com/health/wellness/sunscreen-sun-exposure-skin-cancer-science https://www.outsideonline.com/health/wellness/sunscreen-sun-...
s1artibartfast 4y ago
That is kind of beside the point. You would have to prove that people in cold countries never get any vitamin D from the sunlight throughout the entire year to eliminate it as a factor. You would also have to be able to prove that people people with vitamin D Rich diets are identical to those without them. Without a randomized controlled trial of vitamin D intervention, there is no way to say for sure that people with more or less vitamin D are seeing a benefit from the vitamin itself, and not some other hidden Factor.
- tinus_hn 4y ago
  Of course it is possible to give a randomized portion of subjects additional vitamin D and the rest a placebo and see if one portion is less likely to develop a disease than the other.
  - s1artibartfast 4y ago
    Of course, which is the point that I am making as well as the grandparent post. Studies which have not done this should be taken with a grain of salt.
suction 4y ago
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t0bia_s 4y ago
Recommend to adults vitamin D intake of 4000 IU (100mcg) daily (or at least 2000 IU) in the absence of testing. 4000 IU is widely regarded as safe. https://vitamindforall.org/letter.html https://vitamindforall.org/letter.html

napierzaza 4y ago

[dead]

tedunangst 4y ago

It's hard to find good answers on actual timelines, but vitamin D is fat soluble and you don't become insufficient after just a week of sitting in the dark.

freeone3000 4y ago
More like six months.
Aldipower 4y ago
I am talking about months of actual lack of sunlight, not a week. I for myself know 2 friends which diagnosed with vitamin D insufficiency. Because we are relatively young this lead to bone problems while doing sports. Without sports it wouldn't be recognized.
- neffo 4y ago
  Interestingly, this was a bit over-diagnosed maybe 10ish years ago. Not saying this was the case, but some doctors were ordering VitD tests, getting results that said below average or below normal and interpreting it as insufficiency.
crazygringo 4y ago
You sure do by February or March though, if the last time you spent an afternoon at the park (or the beach) was late August.

version_five 4y ago

I had thought that it was possible to get vitamin D from moderate sun exposure in the winter and went looking for info to refute your post. Turns out you are right and I was wrong: https://www.nytimes.com/2022/12/06/well/live/vitamin-d-deficiency-winter.html https://www.nytimes.com/2022/12/06/well/live/vitamin-d-defic... People living above the 37th parallel, basically the tropics, may not be getting enough in the winter, because the sun isn't strong enough to provide it.

adriand 4y ago
It’s brutal, I live near Toronto and not only is the winter sun quite weak but sunny days are quite uncommon. Almost every day is grey and overcast. Combine that with short daylight periods and winter becomes quite the gruelling challenge in terms of mental health especially.
- tharkun__ 4y ago
  Weeeellll :) Toronto Harborfront Center is at 43.6397877,-79.3836877,17.12z according to Google. If I look for the southern most part of Germany, that seems to be Oberstdorf which is at 47.3997083,10.2805651,14.08z ;) Or in other words, Germany in terms of natural sun light exposure in winter is way worse than Toronto. In fact, in Germany its dark much earlier and sun comes up much later for longer. I hear cloud cover is very comparable to the Toronto weather you describe so aptly. One of the most populated areas of Germany is at around 51.5, if we wanted to "guess" where aldipower might be from. Going mostly straight up from Toronto, if you want to hit "civilization" at that level, that's Waskaganish, QC or Moosonee, ON a bit more south, right on our beautiful Hudson Bay. I complain less and less about our beautiful country, the more I compare it w/ the world ;)
  - adriand 4y ago
    Wow, TIL. That’s kind of nuts, I just looked at latitude lines because I was sure you had to be wrong but it looks like where I live (which is actually Hamilton) is the same latitude as northern Italy. In fact, it’s almost exactly the same as Florence, where the forecasted highs over the next week are in mid- to high-teens (C). We have a blizzard and most days next week the high is 1 degree. I honestly didn’t realize how much climate is not strictly determined by latitude!

fshbbdssbbgdd 4y ago

Even if there is no sunlight for half the year (and this completely equalizes vitamin D levels in winter), various confounders of sun exposure will still affect a study on vitamin D levels, assuming the study collects some samples during the period when there is sunlight and vitamin D levels vary. Also, the confounders of vitamin D supplementation I mentioned would apply even if you never get exposed to the sun. I think your comment is assuming the vitamin D supplementation is effective, when that hasn’t really been established. We don’t even know that vitamin D has a direct effect on most of the correlated health measures.

_yb2s 4y ago

Our bodies can store enough to make it through the winter if you are replete at the beginning.

iopq 4y ago
That, of course, assumes you don't wear sunscreen during the summer/fall, which I do
- codethief 4y ago
  You might enjoy this article: https://www.outsideonline.com/health/wellness/sunscreen-sun-exposure-skin-cancer-science https://www.outsideonline.com/health/wellness/sunscreen-sun-...

s1artibartfast 4y ago

That is kind of beside the point. You would have to prove that people in cold countries never get any vitamin D from the sunlight throughout the entire year to eliminate it as a factor. You would also have to be able to prove that people people with vitamin D Rich diets are identical to those without them. Without a randomized controlled trial of vitamin D intervention, there is no way to say for sure that people with more or less vitamin D are seeing a benefit from the vitamin itself, and not some other hidden Factor.

tinus_hn 4y ago
Of course it is possible to give a randomized portion of subjects additional vitamin D and the rest a placebo and see if one portion is less likely to develop a disease than the other.
- s1artibartfast 4y ago
  Of course, which is the point that I am making as well as the grandparent post. Studies which have not done this should be taken with a grain of salt.

suction 4y ago

[dead]

t0bia_s 4y ago

Recommend to adults vitamin D intake of 4000 IU (100mcg) daily (or at least 2000 IU) in the absence of testing. 4000 IU is widely regarded as safe. https://vitamindforall.org/letter.html https://vitamindforall.org/letter.html