It's not irrelevant at all, considering that we have access to a far better and more varied diet now, and here are people popping tons of pills to try to... what? They heard that vitamins are good, and automatically assume that more is better. Which it isn't.
You don't have to "get tan" to photosynthesize Vitamin D. And I hardly consider the "Little House on the Prairie" to be scientific.
No, it's not scientific: it's the perspective of someone who actually grew up during the time. If you don't believe someone's memoirs of the time, you can easily go to museums and see the old pictures of people covering themselves against contact with sunlight. I point this out because you described people getting their vitamin D from spending tons of time in the sun outdoors--which obviously was not the case. You only need a few minutes of sunlight to fill your needs (unless you have a metabolic defect preventing you from adequately photosynthesizing vitamin D or you are dark skinned).
Sorry, but for Vitamin D, it can't be done. Photosynthesis, as I recall, generates the equivalent of 20,000 IU/day. Checking "high in Vitamin D" foods shows no way to reach that kind of level by diet.
Photosynthesis produces what you need, no more (because of biofeedback mechanisms, I think).
"Unfortunately, people think that if, you need 20 mg of nutrient X to be healthy, it must be 1000 times as healthy to take 20,000 mg of it. That is simply not true."
A ridiculous exaggeration.
Really? It's not that much of an exaggeration. Have you ever picked up a multivitamin supplement and looked at how much some of the vitamins and minerals exceed the RDA? This one provides 25X the RDA of Vitamin B-6, as well as several times the RDA of several other vitamins. Linus Pauling, a big advocate of the "more is better" belief, took 12,000 mg of Vitamin C, or about 160X the RDA, every day, and on occasion bumped it up to 40,000 mg (~533X RDA).
Neither you nor I know, and we have no way of knowing, how long those changes took, or the extent to which they took place. Homo sapiens of 10,000 years ago had teeth just like homo sapiens of today. You keep asserting a degree of certainty which simply does not exist in science in areas where we simply don't know the whole (or even a significant part) of the story. "Through a glass, darkly" is as good as it gets.
The tooth shrinkage is something I remember from genetics class. Apparently, the shrinkage has accelerated over the last 10,000 years. As far as other changes go, one only has to look up how long ago modern humans settled in various places and note how different they are from the "parent" groups to get an idea of how fast their evolution has occurred. These are not unanswerable questions.
Your absolutist statements sound more like those of a new graduate than a long-term practitioner.
It's been 9 years since I got my PhD, so I don't have quite as much "field experience" as you; however, I've never encountered any PhD who runs around acting like they essentially don't know anything, which you seem to imply is how I should express myself. I have not said a single thing which either is not verifiable (I verify with Google before I post), or which is not implicit in the principles of toxicology and/or biochemistry.
Garbage. We simply DO NOT KNOW what the "adequate level" of Vitamin D really is. New research indicates higher than currently recommended.
"I point this out because you described people getting their vitamin D from spending tons of time in the sun outdoors--which obviously was not the case."
That is exactly the case. People got FAR more sunlight even 75 years ago than we do today. People "covered up to the neck" IN PUBLIC. what went on when "not in public" is another story. And a farmer in the sun from dawn to dark even wearing a longsleeve shirt and long pants got FAR more sunlight than pretty much anyone does today (they called'em "rednecks" for a reason). And his wife out working alongside him did too, despite the long dress and bonnet.
And those "top to toes" clothes certainly did NOT block all sunlight. One of my "hats" is spectroscopy, and I have had my nose repeatedly rubbed in the fact the photons are slippery little bastards, and WILL get where you don't think they possibly ever could.
"Photosynthesis produces what you need, no more (because of biofeedback mechanisms, I think)."
You think??
"Really? It's not that much of an exaggeration. Have you ever picked up a multivitamin supplement and looked at how much some of the vitamins and minerals exceed the RDA?
So some pills have excessive levels. So what?? This does not prove that people as a whole get excessive levels, or take them.
"The tooth shrinkage is something I remember from genetics class. Apparently, the shrinkage has accelerated over the last 10,000 years.
LOL. The study is talking about 100,000 years, and the operate word is "might". Or did you simply not read the first paragraph.
"As far as other changes go, one only has to look up how long ago modern humans settled in various places and note how different they are from the "parent" groups to get an idea of how fast their evolution has occurred. These are not unanswerable questions."
All you can tell from that is that there has been a change in a particular direction, not that the change has been sufficient to overcome subtle deficiencies that the new statistical tools are finding.
"It's been 9 years since I got my PhD, so I don't have quite as much "field experience" as you...""
As I expected. Tell you what, get back to me in ten more years.
"I have not said a single thing which either is not verifiable (I verify with Google before I post), or which is not implicit in the principles of toxicology and/or biochemistry."
Again LOL. Google ain't a science source either (bad grammar deliberate). Even "Google Scholar" is inadequate to actually understand what is going on. As I said, see me in ten years after you have learned that science is not nearly as certain as you seem to think.
And again, your arguments are NOT convincing. There is simply too much epidemiological evidence piling up that higher than current levels of Vitamin D are necessary for optimal health.
As I originally said, I eat a healthy diet (lots of multi-colored veggies), yet my blood "D" levels are abysmally low. So obviously I am NOT getting enough sunlight OR supplements according to the hard physical evidence of bloodwork.
I don't think that a diet consisting solely of fish livers and mackerel is one I could stand (or survive on).
So I'll stick to my supplements, thank you. If I could even get the blood levels up to 25 I'd be happy.