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Vitamin D supplementation to prevent acute respiratory tract infections (2017)

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Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#141

Post by dreamcompiler »

wdobbels wrote: post #101
BurningFrog wrote: post #88

Earlier quoted context omitted.

This is one reason arctic people eat so much (vitamin D rich) fish. The other is of course that a plant based diet is impractical when plants are only alive half the year. White skin itself is an evolutionary adaption for getting enough vitamin D outside of tropical Africa. The extreme "melanin-anemic" blond & blue eyes look of Scandinavia is thought to be because it has a uniquely warm weather for the latitude, whic…

I'm probably missing something obvious but... Should white skin not reflect sunlight more, and dark skin absorb it more? I agree that northerners have more need to absorb sunrays and hence make more vitamin D, so shouldn't they be black?

It's not obvious; this confused me for a long time. The skin we call "white" is fairly transparent to UV, and the skin we call "black" is much less so. Skin is a mixture of transparency and reflectivity at different wavelengths and different depths below the surface. As such it's extraordinarily difficult to model it so it looks right, as any CGI engineer will tell you.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#142

Post by kasperni »

dharma1 wrote: post #111
kasperni wrote: post #33

This is a personal experience. But I've been struggling with constant throat infections, tiredness and coughing every winter for years (I live in a Nordic country). Had my 25-Hydroxy-Vitamin D(D3+D2) checked in both autumn and winter 2 years ago. In October it was ~ 110 nmol/L and in February it was ~ 30 nmol/L. (Deficiency is around 50 nmol/L). Seeing the seasonal difference was a bit of an eye-opener. And I have be…

how high is high dose for you?

4,000 IU 4-5 days a week. I did a loading phase with a bit more.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#144

Post by blaser-waffle »

leto_ii wrote: post #47
TacoToni wrote: post #41

Earlier quoted context omitted.

getting my blood panel ran and finding out i was deficient in Vitamin D changed my life for the better once i start daily supplementation of Vitamin D3 (5000 IU). I even live in Florida, but working in an office all day doesn't help. Now that my levels are good, i feel as if my memory is far better and i dont feel tired all the time.

> i feel as if my memory is far better and i dont feel tired all the time. I agree. Don't overdo it though, 5000 IU daily seems a bit much :) I live in Amsterdam and take 2000.

Canada here. "Central Canada" aka reasonably far up.

2000 IU a day, 3-5 days a week. Not strict about it, just whenever I remember. Big difference in terms of energy, depression, sleep quality, etc.

I've messed around with higher levels but they usually give me wicked headaches.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#145

Post by dreamcompiler »

thinkingemote wrote: post #42
leto_ii wrote: post #21

I can say from my own experience that the lack of vitamin D can have a significant impact on both mind and body. I suspect that essentially all people living at relatively northern latitudes have some sort of vitamin D deficiency. From what I know you need to have your face and arms exposed to direct sunshine for at least 15 minutes/day to keep healthy vitamin D levels in the body. Good luck with that in the European…

Its not possible to get any vitamin D from the sun in the winter in these high latitudes even if you outside in the sun all day with short sleeves. The angle of the sun is too low. We are just beginning march now, so the sun should soon be beginning to be high enough to give some benefit.

It doesn't work in the binary fashion you described. Low sun angles have two results: Cosine effect and greater atmospheric absorption. The cosine effect decreases the watts per square meter you receive, if your skin is not normal (90 degrees) to the incident sunlight. Greater atmospheric absorption means more UVB is absorbed by the atmosphere before it gets to you, but some still gets through, as anyone who has ever been sunburned in the winter can attest. Higher altitudes and snow on the ground both increase the amount of UVB you receive, even when the sun is low.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#146

Post by Florin_Andrei »

wdobbels wrote: post #101
BurningFrog wrote: post #88

Earlier quoted context omitted.

This is one reason arctic people eat so much (vitamin D rich) fish. The other is of course that a plant based diet is impractical when plants are only alive half the year. White skin itself is an evolutionary adaption for getting enough vitamin D outside of tropical Africa. The extreme "melanin-anemic" blond & blue eyes look of Scandinavia is thought to be because it has a uniquely warm weather for the latitude, whic…

I'm probably missing something obvious but... Should white skin not reflect sunlight more, and dark skin absorb it more? I agree that northerners have more need to absorb sunrays and hence make more vitamin D, so shouldn't they be black?

The dark (or not so dark) layer is quite superficial, not far from surface. But the vit D production happens deeper in. For sun rays to get there, that layer must be light-colored.

Sure, some photons do get reflected, but the benefit is from those photons that get deeper into the skin.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#147

Post by Florin_Andrei »

leto_ii wrote: post #21

I can say from my own experience that the lack of vitamin D can have a significant impact on both mind and body. I suspect that essentially all people living at relatively northern latitudes have some sort of vitamin D deficiency. From what I know you need to have your face and arms exposed to direct sunshine for at least 15 minutes/day to keep healthy vitamin D levels in the body. Good luck with that in the European…

I probably had life-long chronically low levels of vitamin D. Taking supplements was a major change for me - basically everything got better.

This sort of thing is impossible to diagnose correctly without lab tests.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#148

Post by abainbridge »

SketchySeaBeast wrote: post #125
abainbridge wrote: post #113

Earlier quoted context omitted.

That seems implausible. Obviously there was evolutionary pressure on northern Europeans to tolerate lower levels of sunlight and no doubt adaption happened. However, I expect even Swedes evolved in an environment that included more time outdoors than a modern Swedish office worker gets. So, in the absence of any actual evidence, I'd still expect a problem. On top of that, there is some evidence. Basically all the pap…

The first two articles I get from that search looks at vitamin d and the older population, and the third[1] suggests that even in sub-arctic elevations "Adequate levels were found in 79.2%, more often in women (82.7%) than in men (75.6%). Only 0.7% of the population were vitamin D3–deficient but 23.1% of men and 17.1% of women had insufficient levels." That doesn't seem too damning. At the end of the day I don't know…

I already agreed there was adaption. I just can't see how there can have been adaption for an _indoor_ life at northern latitudes. That's doubly hard, compared to a traditional life in northern latitudes, right? Although, to argue against myself, I guess if you go far enough north, people won't be getting any sunlight in the winter even if they are outdoors all the time. People there must have adapted to that. I guess by eating things with lots of vitamin D.

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#149

Post by chabes »

Robotbeat wrote: post #126
chabes wrote: post #123

Earlier quoted context omitted.

Ummm, plants are alive longer than “half the year“. Humans have also preserved foods for out of season consumption for millennia. Natives in California had plenty of plant-based foods in winter months.

"California" being the operative word, there. Oslo, Norway has a 60 degree latitude. Sacramento has a 35.8 degree latitude.

Most humans live closer to 27 degrees north of the equator. I mentioned California natives because that’s what I’m most familiar with. Plant preservation is a thing in northern latitudes too..

Re: Vitamin D supplementation to prevent acute respiratory tract infections (2017)

#150

Post by chabes »

bdamm wrote: post #127
chabes wrote: post #123

Earlier quoted context omitted.

Ummm, plants are alive longer than “half the year“. Humans have also preserved foods for out of season consumption for millennia. Natives in California had plenty of plant-based foods in winter months.

Natives in California can still be harvesting in November and can see the ground all year round except in the mountains. Natives at the far north might be done with harvesting by late September or early October and might not see the ground again until April. Not even remotely comparable in terms of the severity of the issue and the impact to survival.

Natives in the far north still preserve food for consumption during winter months.
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