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.
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)
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.
That same mutation made them vulnerable to the levels of sunlight at lower latitudes, susceptible to sunburns, etc.
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.
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).
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.
If a study is going to draw debatable conclusion after 10 years on high dose Vitamin D during pregnancy, I'd expect at least some comment in the study on the general socio economic landscape and grouping.
Regardless, this study looks like a sham to me.
this is right there in the abstract, isn't that the entire game?
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.
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.
Whatever we're doing that isn't what they're doing is not normal.
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.
Plus, studies in US are less scrutinized because researchers are aware of the need for a diverse cohort and you are more likely to get one in the US vs elsewhere.
As they stated, it is because the population of Denmark is very homogenous, as opposed to the US. If you are trying to make a generalization that applies to a range beyond just white people, having Denmark as your sole sample is clearly flawed.
Along the same lines, picking Japan for the purpose of generalizing to wider racial/ethnic groups would also be a bad idea. Not because their research is untrusted/considered non-reputable (it is quite the exact opposite), but because their population is too homogenous.
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).
Spain have lower levels of vitamin d than Denmark.
In places like Spain only some “premium” milk gets this treatment.
pkoird•1h ago
api•59m ago
(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.
georgeburdell•37m ago
bethekidyouwant•27m ago
therein•49m ago
And even clothing.
throwup238•29m 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.
[1] https://academic.oup.com/mbe/article/28/1/29/984822
logicchains•41m ago