If deficiency is linked to all these maladies then why aren’t we seeing them occur with less frequency in areas that get full sun year round?
Vitamin D, part 3 – The Evidence
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Re: Vitamin D, part 3 – The Evidence
#22So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
There is a fundamental difference between vitamin D generated in your skin versus vitamin D placed in your gut. The mechanisms by which it acts and the effects it has on you are probably radically different. We are more than just a pile of various materials.
Re: Vitamin D, part 3 – The Evidence
#23So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
It might just be that the production of vitamin D via sunlight has other effects on the body, perhaps vitamin D has been a proxy for those effects but for obvious reasons taking it as a supplement doesn't trigger the same outcome. It's unfortunate that exposure to UV is so harmful, I'm left wondering if trials using UV lightboxes to stimulate vitamin D production would change the kinds of outcomes (cancer, heart dise…
What is harmful is being indoors all the time, and getting out so rarely that you get sunburned in short amount of time. Far more damage is done by being indoors too much than being outdoors too much.
The white skin has evolved because the body needs sun and UV light to function, one would die otherwise.
Re: Vitamin D, part 3 – The Evidence
#24If deficiency is linked to all these maladies then why aren’t we seeing them occur with less frequency in areas that get full sun year round?
Re: Vitamin D, part 3 – The Evidence
#25I gotta say though... the world would have far less race problems had that odd little quirk of photosynthesis of a key nutrient not existed.
Re: Vitamin D, part 3 – The Evidence
#26So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
That is a reasonable hypothesis. Also, people who are very ill are less likely to get outside and get enough sun, so they will develop low Vitamin D. Vitamin D is likely a marker of poor health. (Once the Vitamin D gets low enough, we do see direct harmful effects from it (think rickets in children), and this may contribute to poor health at that point.)
Re: Vitamin D, part 3 – The Evidence
#27So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
I would frame it in the opposite direction: having a serious illness is correlated with low levels of Vitamin D. People with a serious illness may stay inside more, and go outside less. It's possible that "low levels" of Vitamin D are still within the healthy range, and they merely are an indication of how much time the person has spent outside during the day. In other words, it's possible that Vitamin D is pure symp…
Re: Vitamin D, part 3 – The Evidence
#28TL;DR: skip to the part "The areas in which meta-analyses have identified benefits from Vitamin D" Also "Vitamin D failed to prevent cancer, stroke, heart attack, or cardiovascular death. " Which is fair enough. But at least for the cardiovascular diseases mentioned, I don't think it was expected. And of course, this does not mean anything against the role of Vitamin D in Covid prevention Basically: don't dismiss X f…
Re: Vitamin D, part 3 – The Evidence
#29So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
I would frame it in the opposite direction: having a serious illness is correlated with low levels of Vitamin D. People with a serious illness may stay inside more, and go outside less. It's possible that "low levels" of Vitamin D are still within the healthy range, and they merely are an indication of how much time the person has spent outside during the day. In other words, it's possible that Vitamin D is pure symp…
This is a departure from the discussion of supplementing vitamin D though, isn't it?
I guess the treatment "go out and do sports" is a very different one compared to "X amount of vitamin D per day as a supplement" and the former may indeed be healthy, while the latter may not be, even though they both result in higher levels of vitamin D.
Re: Vitamin D, part 3 – The Evidence
#30So Vitamin D deficiency is linked to cancer, heart disease, respiratory infection, stroke, diabetes, and death. But taking it as a supplement helps with none of the above. What is a reasonable hypothesis then? That having an active lifestyle that brings you outside in the sun both causes your Vitamin D to go up, and is correlated with better physical health in general?
There are thousands of reasonable hypothesis, and it is extremely costly (and in some cases, nearly impossible) to test. e.g. our bodies need sunlight and cholesterol in order to synthesize vitamin D; This process also apparently has some other outputs like NO which are much harder to measure since they get used quickly. It is possible that vitamin D is merely (mostly) a measure of the prevalence of this process, and…