31–40 of 218 posts
Shouldn't they be looking at getting vitamin D via sun exposure, rather than supplementation? If the real benefit is sun exposure, which also increases vitamin D, then just supplementing vitamin D won't show any benefits.
The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case was likely furnished by less vitamin D as we migrated away from the equator. The pressure must have been significant since being white carries a big downside: higher vulnerability to sunburn and skin cancer. When I lived in Cali I always envied my darker skinn…
Humans being humans, I’m sure nose shape, eye color (just ask Bran Sanderson), hair color/texture, or something else would readily suffice in the absence of a perceptible difference in skin tone.
So 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…
Right, that's why I used the word correlated - while it's not unreasonable to think that having an active lifestyle could cause you to be more healthy, it's pretty much a statistical necessity that the two are correlated, because being very sick precludes you from having a lifestyle like that.
Earlier quoted context omitted.
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…
> It's not even necessarily the case that going outside is healthy, but that healthy people tend to go outside more. 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…
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?
So 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?
> How can we reconcile promising early observational studies linking Vitamin D to most major causes of death with our current results? One thing that seems increasingly clear is that in most cases low Vitamin D (truly low Vitamin D) is a marker of poor health rather than a cause. Vitamin D is made in the skin after exposure to sunlight. A chronically ill, frail individual may leave the house less often, leading to lower Vitamin D levels. Fixing the Vitamin D will not fix the chronic illness.
The most obvious evidence to me has always been that Europeans are not black. A change like the loss of melanin requires selective pressure, which in this case was likely furnished by less vitamin D as we migrated away from the equator. The pressure must have been significant since being white carries a big downside: higher vulnerability to sunburn and skin cancer. When I lived in Cali I always envied my darker skinn…