6 ms·

Vitamin D3 During Pregnancy and Cognitive Performance at 10 Years

192 points by supermatou 4mo ago

pkoird 4mo ago
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.
- api 4mo ago
  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. Maybe darker skinned people need to be taking more D supplements.
  - georgeburdell 4mo ago
    Does not explain India where there is high genetic diversity and generally the South is more educated and wealthy
    - bethekidyouwant 4mo ago
      The reason that southern India is generally richer is very complicated.
      - deleted 4mo ago
        [deleted]
  - HexPhantom 4mo ago
    The vitamin D angle seems much more plausible to me as a public-health issue than as an explanation for broad population-level cognitive differences
    - api 4mo ago
      Doesn’t that make a feedback loop though? Poor health equals higher health care overhead, lower productivity, more family issues, and overall worse outcomes all over the place. That in turn is going to make educational outcomes worse and child rearing worse. Some diseases can even have lasting cognitive side effects.
  - deleted 4mo ago
    [deleted]
- therein 4mo ago
  >car travel, air conditioning, sunscreens even And even clothing.
  - throwup238 4mo ago
    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. [1] https://academic.oup.com/mbe/article/28/1/29/984822 https://academic.oup.com/mbe/article/28/1/29/984822
    - ezekiel68 4mo ago
      Still, 170,000 - 1.2M years is a fairly short amount of time if we go back only to the common ancestor who begat progeny that would become Pan and Autralopithecus (around 12 million years ago). It could be that early hide wearers started a trend that, to this day, continues to interfere with natural vitamin D metabolism (while also providing many benefits).
      - throwup238 4mo ago
        Our ancestors started losing their hair about 2 million years ago and the MC1R gene giving us eumelanin pigmentation was fully fixed in the population around 1.2 million years ago by which point we were mostly hairless. In that range is when our vitamin D metabolism evolved, so clothing would have been present for large fractions of our existence. Going back to a common ancestor with monkeys is pointless because their vitamin d pathways are significantly different like 7-dehydrocholesterol secretions that metabolize to vitamin D via external UV exposure and are ingested during grooming.
- logicchains 4mo ago
  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/ https://pubmed.ncbi.nlm.nih.gov/24697969/ . I.e. avoiding sun exposure completely is as harmful as smoking cigarettes.
- HexPhantom 4mo ago
  What I find more plausible is that low sun exposure is one small contributor among many
  - maipen 4mo ago
    Yes, I think that too. Besides sports, most young people studying today are aiming for jobs that are mainly indoors. It's not a requirement, of course, but because a lot of modern careers consist of working in offices or other enclosed environments. No movement, No sun, Stale Air (Unless you have good ventilation). Pretty harmful if we think about it.
Aboutplants 4mo ago
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
- Groxx 4mo ago
  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.
daniel_c_code 4mo ago
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.
- SoftTalker 4mo ago
  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.
  - stephc_int13 4mo ago
    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.
    - ifwinterco 4mo ago
      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)
- gnerd00 4mo ago
  add night time lighting of all kinds..
rhtutjfkroi 4mo ago
[flagged]
- lanfeust6 4mo ago
  I think this type of projection is problematic and regressive. Insights that research provides are a net positive.
  - lloydatkinson 4mo ago
    Don't fall for it by replying; it's a troll, probably automated.
- giwook 4mo ago
  > Pregnant person can do whatever they want with their body. 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.
  - lloydatkinson 4mo ago
    Don't fall for it by replying; it's a troll, probably automated.
  - throe84jrjt 4mo ago
    [flagged]
- lloydatkinson 4mo ago
  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.
  - 4mo ago
soupspaces 4mo ago
https://en.wikipedia.org/wiki/Royal_jelly#Epigenetic_effects https://en.wikipedia.org/wiki/Royal_jelly#Epigenetic_effects
niteshpant 4mo ago
I have thoughts on this 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.
- kloop 4mo ago
  Do they need more vitamin D? I thought they just needed more sun to get the same vitamin D
  - cenamus 4mo ago
    At these latitudes they just get almost none naturally, that's why you need to supplement more
    - kloop 4mo ago
      Ahh, more supplement. I must have misread as more absolute amount
  - nine_k 4mo ago
    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. [1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC8359960/ https://pmc.ncbi.nlm.nih.gov/articles/PMC8359960/
- xwowsersx 4mo ago
  Study seem to have addressed point #2 in several ways. 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
tarkin2 4mo ago
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.
- appplication 4mo ago
  Not necessarily, if the effect was due to exposure to levels beyond what you’d even get in sunnier climates. It also could be possible those in sunnier climates do experience this effect and it was unnoticed, due to political and socioeconomic issues associated with typical equatorial countries
- HexPhantom 4mo ago
  The paper isn't saying vitamin D determines cognition in general, just that there was a modest signal in a couple of memory measures
- aaron695 4mo ago
  [dead]
shiandow 4mo ago
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).
dzonga 4mo ago
high dosage vitamin D in kept me sane (i.e energetic & in the right mood) in the UK where it's usually gloom & drowsy.
- gib444 4mo ago
  What dosage? > in the UK where it's usually gloom & drowsy Luckily this is only September through to July :) ... :(
scythe 4mo ago
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.
p-o 4mo ago
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.
- bootsmann 4mo ago
  > 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.
  - p-o 4mo ago
    Not always, and in this case, the study is very light on details on how the selection process was done. The burden of the RCT is on the research team and the quality of the randomization varies between studies. 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.
jbellis 4mo ago
> the association with flexibility or set shift did not remain significant after false discovery rate correction this is right there in the abstract, isn't that the entire game?
OutOfHere 4mo ago
Meanwhile, the endocrine society is still murdering millions by asking people to not supplement vitamin D3 and to explicitly not test for it either. The times must be tough for endocrinologists with people supplementing high-dose vitamin D3 and testing routinely to ensure an optimal level, tough enough to want to keep people very sick.
jtrn 4mo ago
Can you say p-hacking? It was designed and powered to test whether prenatal vitamin D reduces childhood asthma/wheeze, and found no effect on that primary outcome. The rest is just shuffling numbers and statistical methods around until something with p > .05 pops out. They flags their own post hoc status, reports modest effect sizes, and applies some multiple-comparison correction. That makes the rhetorical sleight of hand harder to spot, because it's buried inside otherwise careful looking work. The statistics are shit. They applied Benjamini-Hochberg FDR correction within cognitive domains, not across the family of 11 functions. That choice is what produced the headline "memory survived correction." Watch what happens with the actual numbers. The two "winning" functions, verbal memory (p = .02) and visual memory (p = .01), both sit inside the memory domain — which contains exactly those two functions. BH within a 2-member family barely adjusts anything: the most lenient threshold is just 0.05, and both p-values are already under it, so the q-values come back at .02 and .02. The correction was toothless by construction, because the two hits happened to fall in the same tiny domain. A reviewer should have made them show the whole-family result side by side. The fact that they didn't is the tell. And there is much more that could be criticized in the same manner across the whole thing. And then the observational data fail to corroborate the supplementation finding. The authors explain the mismatch via trimester timing of exposure, which is plausible, but the equally plausible reading is that the RCT hits are fragile, or that, more probably, it's not a real effect. And even if there was an effect, it's so small and weak and NOT proven by even this data, that the recommendation for supplementation is not warranted at all. At best, this single study with their focus on recreating this effect is the only defensible conclusion. And yet they recommend supplementation.This is pure bias and D-vitamin cult babble once again. The conclusion, based on the actual data, is: in a vitamin-D-sufficient cohort, high-dose prenatal D3 was not associated with offspring cognition on any whole-battery-corrected measure. I hate this so much because it's stupidity like this that shows that science is not worth paying attention to, because the scientists basically lie through their teeth, at least from my perspective, where truth is something that is verifiable and relates to something real.
ck2 4mo ago
the Vitamin D cult is a bit insane it is -exactly- like Linus Pauling and Vitamin C cult in the previous century Vitamin D is very important Too Much is as bad as Too Little The "RDA" is too low at 600IU and should have been changed to 2000IU decades ago It can help prevent certain diseases and illnesses It CANNOT cure any known disease or illness once afllicted
- ezekiel68 4mo ago
  You kind of covered this in your last point but it's worth emphasizing: we generally don't know for sure whether "correcting" a low serum vitamin D reading helps out in some way or merely silences a warning beacon that should have been traced to a more serious underlying condition.
Aurornis 4mo ago
> We found that high-dose supplementation was positively associated with 3 of 11 functions assessed: verbal memory, visual memory, and flexibility or set shift. However, the association with flexibility or set shift was not significant after correction for multiple testing. They tested 11 different measures. Only 3 of those tests showed significance, but after they corrected for multiple testing the significance of 2 of those disappeared. Only 1 test remained below the significance threshold. This is on a set size of about 500 children who completed the study, randomized to the two groups. The only measure that remained statistically significant was visual memory. If you look at Figure 2 it's not even clear that there was a trend toward improvement because everything is so scattered, including a couple measures that were trending worse with higher Vitamin D levels. This study isn't very convincing. It's a classic p-hacking trick to include many different smaller tests so if one of them pops up as an outlier you can claim that something was significant.
- margalabargala 4mo ago
  Relevant xkcd https://xkcd.com/882/ https://xkcd.com/882/
- letmevoteplease 4mo ago
  Where are you getting "after they corrected for multiple testing the significance of 2 of those disappeared"? The text you quoted says, of the three, one disappeared and two remained.
- marcosdumay 4mo ago
  > It's a classic p-hacking trick It's a hypothesis seeking study. It just invalidated 8 of them and picked 1 ok-ish candidate to run an actual study in. The only thing wrong here is there's only one format for submitting a paper.
  - medymed 4mo ago
    And if the 1 ok-ish candidate study turns out to have significant results, publication bias has to be considered: that dozens or more other studies of vitamin D (or whatever) may have not found significant results of previously ok-ish hypothesis candidates and those negative studies are often not published. I think this is quite the case for vitamin D which has multiple physiologic roles and is studied extensively for relation to many categories of health issues. One more reason why it can be stunningly impressive when something/anything health-related is eventually proven.
cortic 4mo ago
Vitamin D excess can lower blood levels of vitamin K2, reducing bone development. Not sure if the levels would be high enough for this (difficult to find safe numbers for in utero), but the side effects, joint pains, stiffness, could have motivated the kids to stay indoors and focus on more intellectual pursuits, leading to better cognitive performance. I point this out because there are so many known factors both positive and negative that contribute to increased 'cognitive performance' it is impossible to account for all of them, even within a randomized trail such as this. People are weak to assumptions when it comes to correlation.
HexPhantom 4mo ago
I'd read this less as "high-dose vitamin D makes kids smarter" and more as "prenatal vitamin D might matter for some neurodevelopmental outcomes, and it’s worth testing more directly"
simianwords 4mo ago
Serious: when I take Vitamin D3 I get all washed up and feel hungover for multiple days. It looks like few people have this reaction. Anyone has any leads on this? Why is this happening? Doctors deny it and my levels are low.

192 points by supermatou 4mo ago

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.

api 4mo ago
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. Maybe darker skinned people need to be taking more D supplements.
- georgeburdell 4mo ago
  Does not explain India where there is high genetic diversity and generally the South is more educated and wealthy
  - bethekidyouwant 4mo ago
    The reason that southern India is generally richer is very complicated.
    - deleted 4mo ago
      [deleted]
- HexPhantom 4mo ago
  The vitamin D angle seems much more plausible to me as a public-health issue than as an explanation for broad population-level cognitive differences
  - api 4mo ago
    Doesn’t that make a feedback loop though? Poor health equals higher health care overhead, lower productivity, more family issues, and overall worse outcomes all over the place. That in turn is going to make educational outcomes worse and child rearing worse. Some diseases can even have lasting cognitive side effects.
- deleted 4mo ago
  [deleted]
therein 4mo ago
>car travel, air conditioning, sunscreens even And even clothing.
- throwup238 4mo ago
  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. [1] https://academic.oup.com/mbe/article/28/1/29/984822 https://academic.oup.com/mbe/article/28/1/29/984822
  - ezekiel68 4mo ago
    Still, 170,000 - 1.2M years is a fairly short amount of time if we go back only to the common ancestor who begat progeny that would become Pan and Autralopithecus (around 12 million years ago). It could be that early hide wearers started a trend that, to this day, continues to interfere with natural vitamin D metabolism (while also providing many benefits).
    - throwup238 4mo ago
      Our ancestors started losing their hair about 2 million years ago and the MC1R gene giving us eumelanin pigmentation was fully fixed in the population around 1.2 million years ago by which point we were mostly hairless. In that range is when our vitamin D metabolism evolved, so clothing would have been present for large fractions of our existence. Going back to a common ancestor with monkeys is pointless because their vitamin d pathways are significantly different like 7-dehydrocholesterol secretions that metabolize to vitamin D via external UV exposure and are ingested during grooming.
logicchains 4mo ago
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/ https://pubmed.ncbi.nlm.nih.gov/24697969/ . I.e. avoiding sun exposure completely is as harmful as smoking cigarettes.
HexPhantom 4mo ago
What I find more plausible is that low sun exposure is one small contributor among many
- maipen 4mo ago
  Yes, I think that too. Besides sports, most young people studying today are aiming for jobs that are mainly indoors. It's not a requirement, of course, but because a lot of modern careers consist of working in offices or other enclosed environments. No movement, No sun, Stale Air (Unless you have good ventilation). Pretty harmful if we think about it.

Aboutplants 4mo ago

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

Groxx 4mo ago
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.

daniel_c_code 4mo ago

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.

SoftTalker 4mo ago
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.
- stephc_int13 4mo ago
  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.
  - ifwinterco 4mo ago
    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)
gnerd00 4mo ago
add night time lighting of all kinds..

rhtutjfkroi 4mo ago

[flagged]

lanfeust6 4mo ago
I think this type of projection is problematic and regressive. Insights that research provides are a net positive.
- lloydatkinson 4mo ago
  Don't fall for it by replying; it's a troll, probably automated.
giwook 4mo ago
> Pregnant person can do whatever they want with their body. 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.
- lloydatkinson 4mo ago
  Don't fall for it by replying; it's a troll, probably automated.
- throe84jrjt 4mo ago
  [flagged]
lloydatkinson 4mo ago
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.
- 4mo ago

soupspaces 4mo ago

https://en.wikipedia.org/wiki/Royal_jelly#Epigenetic_effects https://en.wikipedia.org/wiki/Royal_jelly#Epigenetic_effects

niteshpant 4mo ago

I have thoughts on this 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.

kloop 4mo ago
Do they need more vitamin D? I thought they just needed more sun to get the same vitamin D
- cenamus 4mo ago
  At these latitudes they just get almost none naturally, that's why you need to supplement more
  - kloop 4mo ago
    Ahh, more supplement. I must have misread as more absolute amount
- nine_k 4mo ago
  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. [1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC8359960/ https://pmc.ncbi.nlm.nih.gov/articles/PMC8359960/
xwowsersx 4mo ago
Study seem to have addressed point #2 in several ways. 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

tarkin2 4mo ago

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.

appplication 4mo ago
Not necessarily, if the effect was due to exposure to levels beyond what you’d even get in sunnier climates. It also could be possible those in sunnier climates do experience this effect and it was unnoticed, due to political and socioeconomic issues associated with typical equatorial countries
HexPhantom 4mo ago
The paper isn't saying vitamin D determines cognition in general, just that there was a modest signal in a couple of memory measures
aaron695 4mo ago
[dead]

shiandow 4mo ago

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).

dzonga 4mo ago

high dosage vitamin D in kept me sane (i.e energetic & in the right mood) in the UK where it's usually gloom & drowsy.

gib444 4mo ago
What dosage? > in the UK where it's usually gloom & drowsy Luckily this is only September through to July :) ... :(

scythe 4mo ago

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.

p-o 4mo ago

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.

bootsmann 4mo ago
> 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.
- p-o 4mo ago
  Not always, and in this case, the study is very light on details on how the selection process was done. The burden of the RCT is on the research team and the quality of the randomization varies between studies. 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.

jbellis 4mo ago

> the association with flexibility or set shift did not remain significant after false discovery rate correction this is right there in the abstract, isn't that the entire game?

OutOfHere 4mo ago

Meanwhile, the endocrine society is still murdering millions by asking people to not supplement vitamin D3 and to explicitly not test for it either. The times must be tough for endocrinologists with people supplementing high-dose vitamin D3 and testing routinely to ensure an optimal level, tough enough to want to keep people very sick.

jtrn 4mo ago

Can you say p-hacking? It was designed and powered to test whether prenatal vitamin D reduces childhood asthma/wheeze, and found no effect on that primary outcome. The rest is just shuffling numbers and statistical methods around until something with p > .05 pops out. They flags their own post hoc status, reports modest effect sizes, and applies some multiple-comparison correction. That makes the rhetorical sleight of hand harder to spot, because it's buried inside otherwise careful looking work. The statistics are shit. They applied Benjamini-Hochberg FDR correction within cognitive domains, not across the family of 11 functions. That choice is what produced the headline "memory survived correction." Watch what happens with the actual numbers. The two "winning" functions, verbal memory (p = .02) and visual memory (p = .01), both sit inside the memory domain — which contains exactly those two functions. BH within a 2-member family barely adjusts anything: the most lenient threshold is just 0.05, and both p-values are already under it, so the q-values come back at .02 and .02. The correction was toothless by construction, because the two hits happened to fall in the same tiny domain. A reviewer should have made them show the whole-family result side by side. The fact that they didn't is the tell. And there is much more that could be criticized in the same manner across the whole thing. And then the observational data fail to corroborate the supplementation finding. The authors explain the mismatch via trimester timing of exposure, which is plausible, but the equally plausible reading is that the RCT hits are fragile, or that, more probably, it's not a real effect. And even if there was an effect, it's so small and weak and NOT proven by even this data, that the recommendation for supplementation is not warranted at all. At best, this single study with their focus on recreating this effect is the only defensible conclusion. And yet they recommend supplementation.This is pure bias and D-vitamin cult babble once again. The conclusion, based on the actual data, is: in a vitamin-D-sufficient cohort, high-dose prenatal D3 was not associated with offspring cognition on any whole-battery-corrected measure. I hate this so much because it's stupidity like this that shows that science is not worth paying attention to, because the scientists basically lie through their teeth, at least from my perspective, where truth is something that is verifiable and relates to something real.

ck2 4mo ago

the Vitamin D cult is a bit insane it is -exactly- like Linus Pauling and Vitamin C cult in the previous century Vitamin D is very important Too Much is as bad as Too Little The "RDA" is too low at 600IU and should have been changed to 2000IU decades ago It can help prevent certain diseases and illnesses It CANNOT cure any known disease or illness once afllicted

ezekiel68 4mo ago
You kind of covered this in your last point but it's worth emphasizing: we generally don't know for sure whether "correcting" a low serum vitamin D reading helps out in some way or merely silences a warning beacon that should have been traced to a more serious underlying condition.

Aurornis 4mo ago

> We found that high-dose supplementation was positively associated with 3 of 11 functions assessed: verbal memory, visual memory, and flexibility or set shift. However, the association with flexibility or set shift was not significant after correction for multiple testing. They tested 11 different measures. Only 3 of those tests showed significance, but after they corrected for multiple testing the significance of 2 of those disappeared. Only 1 test remained below the significance threshold. This is on a set size of about 500 children who completed the study, randomized to the two groups. The only measure that remained statistically significant was visual memory. If you look at Figure 2 it's not even clear that there was a trend toward improvement because everything is so scattered, including a couple measures that were trending worse with higher Vitamin D levels. This study isn't very convincing. It's a classic p-hacking trick to include many different smaller tests so if one of them pops up as an outlier you can claim that something was significant.

margalabargala 4mo ago
Relevant xkcd https://xkcd.com/882/ https://xkcd.com/882/
letmevoteplease 4mo ago
Where are you getting "after they corrected for multiple testing the significance of 2 of those disappeared"? The text you quoted says, of the three, one disappeared and two remained.
marcosdumay 4mo ago
> It's a classic p-hacking trick It's a hypothesis seeking study. It just invalidated 8 of them and picked 1 ok-ish candidate to run an actual study in. The only thing wrong here is there's only one format for submitting a paper.
- medymed 4mo ago
  And if the 1 ok-ish candidate study turns out to have significant results, publication bias has to be considered: that dozens or more other studies of vitamin D (or whatever) may have not found significant results of previously ok-ish hypothesis candidates and those negative studies are often not published. I think this is quite the case for vitamin D which has multiple physiologic roles and is studied extensively for relation to many categories of health issues. One more reason why it can be stunningly impressive when something/anything health-related is eventually proven.

cortic 4mo ago

Vitamin D excess can lower blood levels of vitamin K2, reducing bone development. Not sure if the levels would be high enough for this (difficult to find safe numbers for in utero), but the side effects, joint pains, stiffness, could have motivated the kids to stay indoors and focus on more intellectual pursuits, leading to better cognitive performance. I point this out because there are so many known factors both positive and negative that contribute to increased 'cognitive performance' it is impossible to account for all of them, even within a randomized trail such as this. People are weak to assumptions when it comes to correlation.

HexPhantom 4mo ago

I'd read this less as "high-dose vitamin D makes kids smarter" and more as "prenatal vitamin D might matter for some neurodevelopmental outcomes, and it’s worth testing more directly"

simianwords 4mo ago

Serious: when I take Vitamin D3 I get all washed up and feel hungover for multiple days. It looks like few people have this reaction. Anyone has any leads on this? Why is this happening? Doctors deny it and my levels are low.