1. Yes, vitamin D actually controls a lot of bodily functions it’s very easily set aside as not a “main” factor when in reality it actually controls a lot
2. This study was done on women in Denmark only which isn’t a great study subject considering Denmark doesn’t get a lot of sun to begin with so most of these women would already start at very low levels
3. This doesn’t directly correlate to women of color because WOC need higher dosage of vitamin D than white women do. The general range of “good” level of vitamin D that doctors tend to use is related to studies results gotten from white people when in reality brown and black people need way more for their range to be at a normal place.
For point 2: I don't think there's really good or bad places to study it, it might not generalize to sunnier places but the reverse is also true. Presumably the scientists working on this can understand these things (I know in my field I'm aware that studies in the tropics will find different things than studies in Canada).
For my own point: in this study they have like 22 test values but still use the 95% confidence interval. Even on random data there will be a significant result like a third of the time so I think it's easy to interpret these result as more definitive than they are. Not that it's a bad study though (no study will be everything, baby steps like this are important in science).
> This study was done on women in Denmark only which isn’t a great study subject considering Denmark doesn’t get a lot of sun to begin with so most of these women would already start at very low levels
Generally, when a study is done in the US - no one will ever question the location. The moment the study is outside the US, "not US so not generalisable" questions always arise.
> when a study is done in the US - no one will ever question the location
Studies everywhere are now being scrutinized for the participant cohorts because it is now widely recognized that biological differences exist between different groups. Some medications for example aren’t sufficiently studied for effects on women vs men and are being reviewed.
Apparently the pale, semi-translucent skin is a mutation that allowed hominids to live at high latitudes, where darker-skinned hominids would whither due to the lack of vitamins of the D group [1].
That same mutation made them vulnerable to the levels of sunlight at lower latitudes, susceptible to sunburns, etc.
I'm perhaps missing something but if there were a significant connection, wouldn't this mean those in sunnier climates would have better verbal and visual memory?
If there were a connection then I would wager that there are more significant factors, since I have seen or heard of no evidence to assume those in sunnier climates have better verbal and visual memory.
The results of this study seem to show no significant correlation, anyhow.
I'm not sure if there are any research showcasing the effects humanity has had in general due to low sun exposure. From all the benefits of Vitamin D and the recent human behavorial shift leading to low sun exposure (car travel, air conditioning, sunscreens even), there are bound to be new biological or psychological changes humanity is experiencing for the first time.
One study found a difference in mortality between the max-sun-exposure and min-sun-exposure cohorts: the second was twofold higher, which is comparable to the effect of cigarette smoking. https://pubmed.ncbi.nlm.nih.gov/24697969/ . I.e. avoiding sun exposure completely is as harmful as smoking cigarettes.
I've wondered for a while if the apparently higher cognitive performance and resulting societal wealth at higher latitudes might be some kind of second order side effect from long-term selection for lower sun exposure. We already know this vitamin D is almost certainly why Northern peoples evolved lighter skin.
(I realize this is a frought topic, so please hold the race science bullcrap replies or the over-reactions in the other direction. I am not a believer in hard biological determinism or "race science," but I also don't dismiss the existence of variations. As with everything else in population genetics and biology, any variations that do exist probably have more than one cause.)
If there's any truth to this, it might be further compounded as people with darker skin spend more time indoors in the modern world. If you have darker skin you need, as far as I know, more sun to make vitamin D, which normally is not a problem if you're outdoors near the equator.
Tailored clothing is at least 80,000–170,000 years old based on genetic clock research in body lice [1] but archaic humans have probably been wearing hides for at least a million years (there’s currently a big debate about how they managed to migrate to colder climates like Spain 800k-1.2m years ago).
I don’t think clothing is that big a factor because all humans in hot environments adapt and very little survives in the archaeological record. Many populations lived in heavily forested jungles where they was little sun exposure and those in deserts used stuff like Otjize for sun protection. Given all the ethnographic reporting from the age of exploration, tons of that clothing was probably made of feathers, cordage, bark, and other materials we wouldn’t even think of using for clothing.
Tangentially, with ai tools available, post hoc secondary analysis of studies (like this) has to be insanely easier to run through. Are there are companies/individuals focused on this specifically? Obviously most labs are doing some of this but I’m curious if there are broader analysis being done
tbh I'd expect the opposite - inherent bias / regression to the current norm comes through quite consistently when they're used to summarize stuff, and that'll badly taint science using it.
I don't know, the study seems pretty mild in findings and the research doesn't mention anything about the socioeconomic environment in which each of the children grew in.
Maybe it's the high dose vitamin, maybe it's because one cohort was skewed one way on the socioeconomic spectrum, maybe it's something else entirely. More evidence would be needed imo to confirm Vitamin D3 has a direct contributor to cognitive performance as the research portrayed.
> the research doesn't mention anything about the socioeconomic environment in which each of the children grew in.
The main trick behind randomized control trials is that you can disregard factors like this because these effects would be randomly distributed as well.
Based on how many tests they did and the confidence intervals they got it's associated with fuck all. Doing lots of tests and then pointing to the few where the lower bound of the effect size was marginally above 0 proves very little.
At any rate their main marker for intelligence showed an impressive p=90%, so whatever cognitive effects were present they've not made them any smarter (at 10).
I guess I don't understand why this study is suddenly getting attention when these kinds of trials have been going on for years. This one doesn't seem to have a particularly strong methodology or particularly unusual findings. It's just another page in a very, very long record of evidence about vitamin D, and by no means settles any major controversy.
This is exactly what I've been thinking about lately. The modern knowledge-worker lifestyle is practically an experiment in extreme sun deprivation. We optimize our indoor spaces with perfect AC, ergonomic setups, and even custom ambient noise apps just to stay locked in a room for 10 hours a day doing deep work.
It makes you wonder how much of what we accept as "normal" afternoon brain fog or tech burnout is actually just our biology reacting to this massive behavioral shift and lack of natural light.
We also evolved to have activity levels that vary a lot more. A neolithic human wouldn't have done 8 hours straight of labor, or slept 8 straight hours at night. A few naps throughout the day would have been common, and sleep was often split in half as well.
It's one huge perk of working from home. Lying down for 20 minutes makes the rest of the day much more pleasant and productive.
Check the CO2 levels in your office. They can get ridiculously high indoors when humans gather in the same room. It's not dangerous, but it makes people tired, they stop taking initiative, and less creative.
Myopia is one that comes to mind, with data suggesting that low exposure to natural sunlight contributes. Though in my case, I played outside a lot as a kid and I still have terrible eyesight.
It is not about sunlight or UV. And it is not "just genetics".
The natural rest position of the human eye is to focus at the infinite.
Focusing on closer objects like books or screens requires a constant effort (we don't feel it).
The eye simply adapts and elongate to relieve some of the strain. Wearing corrective lenses further amplify the process.
If you want your kids to have perfect vision they should spend a lot of time playing outside, until early adulthood.
Yeah I'm not sure what currently "science" says, but from first principles something along these lines must be true, because "genetics" can't explain why some places like China went from low levels of myopia to extremely high levels in a couple of generations.
Clearly there's some significant environmental factor, and constantly focusing at short distances and/or getting no bright light exposure are the two obvious candidates (in other words, being inside all the time)
That's not recent knowledge worker problem. It started with industrial revolution and working 16 hours work days on a dark factory floor. What about Bedouins and other desert dwelling people? They had been trying to reduce sun exposure with complete body skin cover for millenias, it must have been some benefit for that.
And what about skin cancer rates, it is probably reduced due to low sun exposure.
Before anyone gets in a stress, this is obviously some low life engagement bait troll. It might even be totally automated. It saw the word "pregnant" and decided to start on some diatribe about it without even reading the content of the link.
I am really sad that even HN is the target of this type of bullshit.
1. Yes, vitamin D actually controls a lot of bodily functions it’s very easily set aside as not a “main” factor when in reality it actually controls a lot
2. This study was done on women in Denmark only which isn’t a great study subject considering Denmark doesn’t get a lot of sun to begin with so most of these women would already start at very low levels
3. This doesn’t directly correlate to women of color because WOC need higher dosage of vitamin D than white women do. The general range of “good” level of vitamin D that doctors tend to use is related to studies results gotten from white people when in reality brown and black people need way more for their range to be at a normal place.
For my own point: in this study they have like 22 test values but still use the 95% confidence interval. Even on random data there will be a significant result like a third of the time so I think it's easy to interpret these result as more definitive than they are. Not that it's a bad study though (no study will be everything, baby steps like this are important in science).
1. They measured maternal vitamin D before supplementation began. They explicitly adjusted for these preintervention levels.
2. the two groups started at essentially the same vitamin D levels.
3. They specifically tested whether baseline vit D status changed the effect of supplementation
Generally, when a study is done in the US - no one will ever question the location. The moment the study is outside the US, "not US so not generalisable" questions always arise.
Studies everywhere are now being scrutinized for the participant cohorts because it is now widely recognized that biological differences exist between different groups. Some medications for example aren’t sufficiently studied for effects on women vs men and are being reviewed.
That same mutation made them vulnerable to the levels of sunlight at lower latitudes, susceptible to sunburns, etc.
[1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC8359960/
this is right there in the abstract, isn't that the entire game?
If there were a connection then I would wager that there are more significant factors, since I have seen or heard of no evidence to assume those in sunnier climates have better verbal and visual memory.
The results of this study seem to show no significant correlation, anyhow.
(I realize this is a frought topic, so please hold the race science bullcrap replies or the over-reactions in the other direction. I am not a believer in hard biological determinism or "race science," but I also don't dismiss the existence of variations. As with everything else in population genetics and biology, any variations that do exist probably have more than one cause.)
If there's any truth to this, it might be further compounded as people with darker skin spend more time indoors in the modern world. If you have darker skin you need, as far as I know, more sun to make vitamin D, which normally is not a problem if you're outdoors near the equator.
And even clothing.
I don’t think clothing is that big a factor because all humans in hot environments adapt and very little survives in the archaeological record. Many populations lived in heavily forested jungles where they was little sun exposure and those in deserts used stuff like Otjize for sun protection. Given all the ethnographic reporting from the age of exploration, tons of that clothing was probably made of feathers, cordage, bark, and other materials we wouldn’t even think of using for clothing.
[1] https://academic.oup.com/mbe/article/28/1/29/984822
Maybe it's the high dose vitamin, maybe it's because one cohort was skewed one way on the socioeconomic spectrum, maybe it's something else entirely. More evidence would be needed imo to confirm Vitamin D3 has a direct contributor to cognitive performance as the research portrayed.
The main trick behind randomized control trials is that you can disregard factors like this because these effects would be randomly distributed as well.
At any rate their main marker for intelligence showed an impressive p=90%, so whatever cognitive effects were present they've not made them any smarter (at 10).
It makes you wonder how much of what we accept as "normal" afternoon brain fog or tech burnout is actually just our biology reacting to this massive behavioral shift and lack of natural light.
It's one huge perk of working from home. Lying down for 20 minutes makes the rest of the day much more pleasant and productive.
Check the CO2 levels in your office. They can get ridiculously high indoors when humans gather in the same room. It's not dangerous, but it makes people tired, they stop taking initiative, and less creative.
The natural rest position of the human eye is to focus at the infinite. Focusing on closer objects like books or screens requires a constant effort (we don't feel it).
The eye simply adapts and elongate to relieve some of the strain. Wearing corrective lenses further amplify the process.
If you want your kids to have perfect vision they should spend a lot of time playing outside, until early adulthood.
Clearly there's some significant environmental factor, and constantly focusing at short distances and/or getting no bright light exposure are the two obvious candidates (in other words, being inside all the time)
Whatever we're doing that isn't what they're doing is not normal.
Yes, they can. But whatever they are doing to their body, they are doing to their baby as well.
Can they drink and smoke while they are pregnant? Sure, it is their choice.
Should they? Perhaps not, if they care about the welfare of the little human that is growing inside of them.
I am really sad that even HN is the target of this type of bullshit.