We're learning more about what Vitamin D does | Hacker News Reader

We're learning more about what Vitamin D does

technologyreview.com

224 pointsBrajeshwar207 comments

I have polymorphisms in a gene called CYP2R1 (Vitamin D 25-hydroxylase, involved in activation of vitamin D precursors). My polymorphism lead to lower levels of D3.

My doc put me on 1000mcg of D3 a day for a month after I tested low. I came back in for blood testing and my Calcium levels were extremely high (Not good!). So the doctor ordered me to stop the vitamin D to see what was going on.

As it turns out I have even more lower frequency polymophisms in a gene called CALCA (Calcitonin is a peptide hormone that causes a rapid but short-lived drop in the level of calcium and phosphate in blood by promoting the incorporation of those ions in the bones.). So basically since I do not realease a lot of Calcitonin naturally I need to get it from food.

Guess what food is extremely high in Vitamin D3[1] and Calcitonin[2]?

Salmon! I have a genetic history of people that ate a lot of salmon so this makes sense.

Genetics matter people. I will assume that most people who have irish/britsh should be getting their D3 from fatty fish since sunlight is so rare there.

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC6566758/ [2] https://en.wikipedia.org/wiki/Salmon_calcitonin).

I live in the tropics and there is plenty of sunshine here. So my skin doctor told me to avoid the sun at all costs, always wear suncreen and a hat, don't go out in the daytime. A few years of that and now I have a vitamin D deficiency.

Yea sun damage and cancer vs. vitamin d deficiency is a little bit of a balancing act. It also doesn't help skin color is very critical part in all of this but people view that topic as taboo to discuss. The entire reason for skin color variations is a genetic optimization for UV absorption at specific latitudes vs sunburn risks.

That and the other half of the problem is we are all sedentary as hell in all latitudes these days. Be it people hiding under AC at the tropics or hiding in heated homes in the north. We don't go outside to get enough sunlight and our fat reserves that store vitamin d don't grow large enough because we still don't go outside when the weather is tolerable.

I don't think anyone is making it taboo to say someone's melanin content affects how they absorb UV light. It's taboo when you tie it to all sorts of other things, say, how well they should do at school.

> It's taboo when you tie it to all sorts of other things, say, how well they should do at school.

Vitamin D deficiency might affect how well you do in school though and skin color affects that a lot. People who don't live in their native environment get such issues, just like white people getting burnt easily if they move south.

> The entire reason for skin color variations is a genetic optimization for UV absorption at specific latitudes vs sunburn risks.

This seems obvious but was not confirmed by genetic evidence. The rate of adaptation turns out to be much higher than can be explained by skin cancer.

The real cause appears to be fertility. UV radiation breaks down folate (vitamin B9) in the bloodstream, and folate is critical for DNA synthesis and repair. Folate deficiency causes serious problems in pregnancy, neural tube defects like spina bifida, and may impair sperm production. So darker skin in high-UV equatorial regions likely evolved partly to protect reproductive capacity.

In the other direction, lower melanin production helps with vitamin D synthesis in lower sunlight environments. Vitamin D requires UV-B radiation to be synthesized in the skin, and melanin inhibits this. Vitamin D is also linked to fertility. It's involved in sex hormone production and has been associated with successful implantation and pregnancy outcomes.

If you're curious, check out Nina Jablonski and George Chaplin's work. Their hypothesis is that skin color evolution as fundamentally about reproductive fitness: dark enough to protect folate, light enough to synthesize vitamin D. Both nutrients affect fertility, fetal development, and offspring survival. They have an immediate primary impact on fertility and success, while skin cancer even in the most extreme environment/phenotype mismatch, has an onset after reproductive age.

Wearing sunscreen might be a good idea if you are white ethnicity (that is your ancestors lived in northern Europe for thousands of years).

For others. It depends.

Native South Americans, Africans and Indians seem to get skin cancer at much lower rates.

It is what killed Bob Marley

Not all skin cancers are caused by UV exposure, and in particular acral lentiginous melanoma, which is what killed Bob Marley, almost certainly never is.

Can supplement D easily, together with K2.

Careful with this I took vitamin d every day no problem for a year. Randomly started getting heart palpitations one week and was trying to figure out why. Got an Apple Watch to monitor for a fib. Was asking myself what changed in my life that it happened all of a sudden and realized I had started taking K2. ChatGPTs theory is that it really made the absorption of vit d effective and led to hypercalcemia.

Stopped taking vit d and k2 it resolved after a week no problems almost a year later.

You’re warning people to be cautious of taking Vitamin D… because you had problems with potassium supplements? Those are entirely different things with entirely different risk profiles.

K2 isn't a potassium supplement

K2 is synthetic cannabinoid inspired by THC

I mean, you're not wrong, but that's not what the discussion is about.

There's Vitamin K1 and Vitamin K2. Vitamin K2 is frequently taken alongside Vitamin D.

It should be the opposite, not taking K2 leads to calcification as K2 helps your body absorb calcium instead of lingering in your circulatory system.

well that would imply that these LLMs could be wrong and they should talk to a doctor instead - lunacy!

Anyone reading any of this ignore it all and see a doctor/cardiologist/emergency if concerned.

Yea actually it was a while ago I think ChatGPT actually pointed out I was low on magnesium from vit d + k2 requiring/depleting more than usual leading to the palpitations.

Biggest takeaway is it’s easy to hit toxic levels when taking supplements so be careful.

people should actually be more careful about taking medical advice from an LLM than grabbing a vitamin D supplement.

Reminder that the FDA recommended daily allowance of vitamin D is 10x lower than it was supposed to be, because of a math error, and they have never corrected it.

https://pubmed.ncbi.nlm.nih.gov/28768407/

Between the vitamin D error (this affected US and Europe and probably more places) and the sodium/blood pressure study that was misleading if not outright false, it's amazing how a few data points can become widespread advice without much verification and follow-up.

I'm sure there's tons more cases that we don't even know about, not in the conspiracy sense, but more in the sense that there's some issues with how carefully these claims are validated before they get put out there as a rule to be followed.

One of the big issues is the momentum. Even long after these misstakes have been found doctors still give advice based on the error.

Doctors giving advice based on mistaken or otherwise bad data and outdated guidance is a pervasive problem

Let alone meddling vested interests, e.g. with RDA for sugar.

Those are two recommendations out of how many? And how many years? How many errors do police make? Actuaries? Security researchers?

Vitamin D and sodium are examples out of a couple core nutrients, and I could list other nutrients such as sugar or fat too. So the rate is not excellent.

> How many errors do police make? Actuaries? Security researchers?

They make plenty of mistakes too. What's your point?

The abstract wasn't clear to me, but looking it up FDA recommends 20mcg = 800 IU, and the paper recommends 8000 IU. It seems like others are more conservative (7000 IU).

I don't think I've ever seen the 20mcg rec, everywhere I've seen was something like 2000 (and that's what the supplements come as), but P appears correct.

What was the math error that led to this? And I'm curious now how to get 8000 IU. Just take a bunch of pills all at once in the morning?

The paper referenced Finland, which seems like a strong confirmation of safety, but the best information I could find was https://www.ruokavirasto.fi/en/foodstuffs/healthy-diet/natio... . What effective IU dose are people getting in Finland with these changes?

> I don't think I've ever seen the 20mcg rec

The 20mcg rec (the wrong rec) is quite literally on every single nutrition label in America that has Vitamin D. Maybe you haven’t noticed it. Surely you’ve seen it if you’re in the U.S.

https://www.fda.gov/food/nutrition-facts-label/daily-value-n...

> What was the math error that led to this? And I'm curious now how to get 8000 IU. Just take a bunch of pills all at once in the morning?

Read the paper I posted. And it is easy to find 5000iu and 10000iu capsules at a drug store.

> it is easy to find 5000iu and 10000iu capsules at a drug store

Not in Canada!

Good to know. Guess there are still a few good things about American healthcare system

What I don't understand is how it's possible for 90% of people to have a vitamin D deficiency, or whatever that crazy number was. Surely by that point it's just normal?

Modern life is spent indoors whereas historically during our evolution it was outdoors

I don't know how it was approached for vitamin D, but it's all about the model they choose, which in the first instance is just something they pull out of thin air. For many water soluble vitamins and minerals the model is based on a threshold for urine excretion; up the dose until the study group is excreting as much as they take in. Until someone figures out otherwise--i.e. that it's too little, too much, or that other considerations need to be made--that's the basis for the RDA.

Its also normal to be overweight and need glasses, doesn't mean that it isn't a problem.

> What I don't understand is how it's possible for 90% of people to have a vitamin D deficiency

If everyone is being told to get 10x less vitamin d than they really need, seems easy

Most people arent supplementing Vit D, so the recommendations are not relevant to deficiency status.

Set aside pills.

Vit d deficiency is a known problem because of our indoor lives and sunscreen culture, so FDA requires by law supplementation of foods. Like milk. But because the RDA is wrong, these foods get supplemented with insufficient amounts.

Case in point, seasonally adjusted the typical American gets in a day average ~1800iu from the sun and ~200iu from supplemented dietary intake (2000iu total, deficient). If we were to acknowledge the RDA is wrong then milk etc could have 30x more supplementation bringing the average up and filling the gap better

What does "low vit D" mean when there aren't any negative effects of it?

People use clothes now.

I remember this article about Vitamin D says nobody is certain whether it actually does anything:

https://www.nytimes.com/2022/07/27/health/vitamin-d-bone-fra...

Unless you're non-native and have redhead-style very white skin or some history, the doctor sounds overly cautious to paranoid.

Hundreds of millions live in such climates (including people with fairer skin) and have no problems, even though they don't do anything extreme like "avoid the sun at all costs, always wear suncreen and a hat, don't go out in the daytime".

I'm white and I lived near the tropics for a few years, big white and asian population, everybody was out in the sun all the time, hardly covered too. Skin cancer stats as good as Europe or US.

I think we’re starting to find that the “if you get sunlight you will develop skin cancer” mantra is way overblown, if not outright wrong. Being out in the sun is good for humans. In fact, we need it. But modern life largely conspires to prevent it for most of the developed world. Even when we do, we slather ourselves with sunscreen that might be doing more harm than good. Better to wear long sleeves and a hat that you can take off and at least get reflected sunlight while wearing. Oddly, it turns out that our bodies have been tuned to survive outside. Whodathunkit?

Here’s my hypothesis: it’s not total sun exposure that causes issues, it’s inconsistent sun exposure. Those of us in northern climates experience an annual cycle of very high and then nonexistent sun exposure. This causes our skin to stop producing melanin during the winter and then leaves us vulnerable to sunburn in the spring and summer. If we had year-round sun then our skin would consistently maintain melanin levels and we wouldn’t have sunburn.

I’d love to know if there are any studies trying to answer my question.

It’s just sunburns that cause skin cancer. It’s really that simple.

That's .. just not true at all.

While the cause is UV exposure, sunburns drive most of the actual risk.[1] so it not technically true that skin cancer is only caused by sunburns, most melanomas come from sunburns. There’s a very linear dose response.

[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC2873840/

More accurately, “sunburn events”.

This, and we are staying inside most of the time, so when spring arrives, we won't have gradual exposure but exposure all at once on the first sunny weekend we decide to get some sun.

Funny story. I started doing the couch to 5k running plan a few years back in January. Come March I realised I'd actually managed to get a tan (living in the outskirts of London, UK being further north than practically all of the inhabited North Americas).

Just being outside in whatever the weather consistently for 30 minutes or so every other day.

This is precisely the picture that I seemed to get when looking at this in depth some time ago. Most meta-reviews highlight a correlation between _number of blistering sunburns_ and melanoma. Not between actual amount of UV exposure. You may think that they’re the same, but they’re not. In fact, the same meta-review was noticing weak anti-correlation between chronic sun exposure and melanoma, I.e. people who work outside shirtless actually have better odds than baseline.

Most risk seems to come from occasional exposure to extremely strong sunlight compared to your day-to-day baseline. Practically speaking, if your skin is able to tan, absorbing as much sunlight as your environment allows for most of the year, with the intrinsic gradual build-up over spring, should be harmless if not even beneficial.

Of course, this highly depends on your genetics and your location. Avoid sunbathing around the equator regardless. And if you’re physically unable to tan, as some people do, then this might not be true either. I couldn’t determine that as easily.

I’ve read the exact opposite of this claim in tons of papers. What are you looking at?

Probably ones not sponsored by the Big Sunscreen

For example this one:

https://doi.org/10.1093/ije/dyp166

It’s a decently big meta-review. It cites studies which more or less say exactly what I said very early, e.g. https://doi.org/10.1007/BF02071515

I might be completely wrong, of course. I’d rather be proven wrong than stay ignorant, so please do share the studies you had in mind.

I have known quite a few people personally who have found (and removed) skin cancer.

I don't know if that means anything, it isn't n=1 sample size, it is more and my gut says it might be statistically significant.

I agree. When it is sunny, I get at least 20 min of sun on my bare skin and in my eyes (not protected from UV by glasses) every other day as recommended by neuroscientist Andrew Huberman. I am however careful not to get a lot more than that at once and have high-UPF clothing, hat and sunglasses to protect myself if I ever do need to be out in the sun for an extended period. (I am of Northern European ancestry.)

Even though I believe that the vitamin D we can buy in bottles is probably just as good as the vitamin D my skin makes, I do not consider vitamin D supplementation an adequate replacement for getting UV light on my skin and in my eyes because vitamin D production is only one of the benefits of getting UV light on the skin and in the eyes. (BTW I think HN put way too much emphasis on vitamin D.)

There are UV light receptors (that use a compound called neuropsin to sense the UV light) on the skin and in the parts of the brain that receive UV light (which gets into the skull mainly through the eyes). These receptors have nothing to do with vitamin D. Getting UV light onto these receptors is a more potent trigger for the release of endorphins in the brain than exercise is.

Regular UV light exposure also increases levels of sex hormones in men and in women. In men, increasing testosterone increases optimism and motivation and drive. Again, IIUC this effect has nothing to do with vitamin D.

When people eat plants, the compounds (e.g., lutein, zeaxanthin and lycopene) that plants use to protect themselves from UV light and blue light tend to be absorbed and to end up in high concentrations in the retina. If you do what I do, namely, get UV light from the sun every other day in moderate doses, then I suggest making sure you are getting plenty of these compounds. (Alexis Cowan says that omega 3 is helpful here, too.)

> I get at least 20 min of sun on my bare skin and in my eyes (not protected from UV by glasses) every other day as recommended by neuroscientist Andrew Huberman

Andrew Huberman peddles nothing more than pop-science supplement grift. I highly recommend you get your health info from somewhere other than bro-optimization podcasts and "light therapy" hucksters.

> I think we’re starting to find that the “if you get sunlight you will develop skin cancer” mantra is way overblown, if not outright wrong.

Citation needed

There's a hole in the atmosphere where I live. Incidentally, one of the highest skin cancer occurrences in the world.

Calling it overblown, is... A dangerous sentiment.

We tore a hole in our atmosphere. This is not the natural way of things, no. But we do have to live with the consequences.

You live in Antarctica?

Not literally above me, no.

But considering it affects everyone, its not something to ignore - especially in a region that is already 10% more UV intense than most of the world.

You do know that the 'ozone hole' got fixed, right? It's not back to baseline, but the Montreal Protocol is one of the major achievements of collaborative science and eco-politics of the late 20th century.

There is some global thinning, but it's minor. If you don't live literally at the south pole where the actual hole is, it's not a huge change compared to most other sources of skin cancer risk.

You do know its still healing right? Which is not past tense?

You do know that this is a Wendy's, right?

Unless you live in Antarctica it doesn't "affect you" in the skin cancer from sun exposure way, just in the "general climate issue" way. And we're not discussing that here.

Unless you live in Antarctica, the above is simply not true...

Big old hole in the ozone layer right over North East Australia, I see dark skinned south Americans blistering because they spent too long in the sun.

Legend has it why Aussies call the English Poms, short for pomegranate, because they come over and get burnt to shit, end up bright red.

> Legend has it why Aussies call the English Poms, short for pomegranate, because they come over and get burnt to shit, end up bright red.

I love Aussies’ sense of humour!

Skin cancer is no joke, but I don’t wear much sunscreen because I don’t need to. I need all the vitamin D I can get. I wish I would’ve protected myself more earlier in life, though.

Having lived in the UK and Australia, they're not kidding when they have don't get skin cancer promotions. The most remembered one from my youth is Slip, Slop, Slap. So Australian. Slip on a shirt, Slop on some suncream and Slap on a hat.

And yet mostly living in Australia, (was only in the grey UK from 2.5 years in our 20's), I'm still vitamin D deficient, because the majority of my life I've been inside on computers, presumably like a large percentage of Hacker News readers.

Ironically, our suncream QA is crap and all of the supposedly good sunscreens with high SPF factors failed indepdent testing - even including the one recommended by the Cancer Council.

The sunscreen thing is atrocious, about 7 years ago I bought a big expensive bottle of LeTan spf50 waterproof sunscreen, had a big day at the beach but applied and reapply diligently following the instructions.

Burnt to a crisp, I emails them and never heard back, I can't image I was the only person to notice.

Which is why Im probably vitD deficient too, the sun is toobharde to spend any amount of time outside unprotected here.

It's now slip, slop, slap, seek, slide - shade and sunglasses!

Same is a great part of the culture.

I'm also in the same boat but more out of laziness and hating being greasy.

Definitely wish I'd been more sun smart when younger though.

> why Aussies call the English Poms

Many years ago I read that it's POME: Prisoner of Mother England, now shortened to just "pom."

I like that too, one day I'll look it up.

whereas i heard it was POHM (Prisoner of Her Majesty) stencilled on clothing and articles of folks who had been "transported"..

Two points.

You can’t say somone is being over cautious without k owing their location. It’s easier to supplement vitamin D than cure skin cancer. If the local population looks different to you there is reason to pause.

Secondly Asian people, East and South, are sun adapted. East Asians may not be dark but they, like Northern Europeans, selects for their current appearance based on environment. Just because they are not brown does not mean they aren’t sun adapted for their locale in ways visitors are not.

Here’s the American association of dermatology recommendation. They say don’t try to get your vitamin D from the sun. https://www.aad.org/media/stats-vitamin-d

I can’t really check for the studies right now since I’m on the phone, but I distinctly remember being interested in the theme of skin cancer due to personal reasons, and that studies found that great exposure to the sun, although slightly increasing the risk of benign skin cancer, does greatly decrease the incidence of non benign skin cancer.

Well, supplementing vitamin D surely is cheaper than dealing with accelerated skin aging and cancer. Unless your doctor is a vampire, I presume they didn't mean to imply you should never go outside, but rather avoid any direct sunlight. I suspect the shade and sunscreen wasn't the issue.

https://open.substack.com/pub/takecontrol/p/dermatologys-war...

I have never wanted to flag a comment on hacker news more. Do you also recommend that people smoke based on... nothing but feelz?

I am 50. I had to have skin cancer removed from my face. I have never seen a more busy doctors office than this dermatologist's office. They were printing money. The waiting room was always full, half filled with men in their 50s up (so probably not getting cosmetic dermatology surgery). Some had noses/ears missing. Granted I grew up surfing in Santa Cruz. But don't think 'skin cancer isn't a thing'.

And the follow up discussion here. Do people here not have parents? Do you not talk to ANYONE over 50 about their lives? Skin cancer is actually real and common and scary AF.

I used to live there and the common consensus was:

- don't stay out in the sun too long, if you do, apply sunscreen

- 10-15 minutes of sunlight exposure a day is completely fine

We only need a few minutes sun exposure in the Australian sun at a UV Index of 14 for vitamin D. 20 minutes to start burning. Maybe there's a happy medium between a bit of sun exposure and no sun exposure.

The trick is to put sunscreen on the most exposed areas of the body face and upper surfaces, the rest through one layer of clothing e.g. tshirt for enough for vitamin D. It only needs 30mins to one hour exposure arms and legs per week

There is a 5000 years old epic called Ramayana which dedicates a significant part of it to a conversation between the protagonist Ram and his guru, agastya.

The summary of that entire conversation is this:

If you ever feel demotivated, defeated or dull just pray to the sun or go into the sunlight.

This message was repeated dozens of times over and over with various metaphors.

I think they were trying to hammer the point that sunlight solves a lot of issues.

interesting ... i am acquainted with ramayana on account of growing up in india but wasnt aware of this sunlight recommendation in it

Almost certainly not that old. Around 2500-2000 years old.

I’ve wondered whether vitamin D is a real time signal within the circadian rhythm regulation system. Perhaps it is released in response to sunlight in order to let other parts of the system know it is daytime.

If it were like this, bulk dosing would be expected to be better than nothing (“maximum daytime!!!! Followed immediately by a very long slow sunset at whatever curve it is cleaned up in the body), but it would be better to dose continuously in real time at a level and body location(s) that would simulate the range of sunlight throughout the day.

Can anyone professionally familiar with the research in this area comment?

Vitamin D interacts with clock genes, which regulate the body's daily rhythms, through its ability to modulate the expression of genes like Clock, Bmal1, and Per2.

https://pmc.ncbi.nlm.nih.gov/articles/PMC11990303/

https://open.substack.com/pub/takecontrol/p/dermatologys-war...

I am impressed how many pop-ups one can serve at once...

Btw not a very revealing article. Basically, saying Vitamin D is important but it's difficult to know how much.

Didn't learn anything more about Vitamin D as the headline suggested.

I closed the webpage after the fourth one, sometimes I really hate what the mainstream web has become.

It helps to just block all javascripts bt default

Doesn't it make some websites unusable? Feels tedious to know when to turn JS on and when off.

You can have off-by-default with an allowlist. After the initial period most of your sites that need JS will be on the list.

> Vitamin D is important but it's difficult to know how much.

My GP recommended one Vitamin D3 1000iu tablet per day. They are very cheap (£1.15 for 60 in the UK).

And where did they get that from? Seems quite random.

It’s interesting that his doctor wouldn’t prescribe a vitamin D supplement because it would supposedly be too expensive for the health care system. Fortunately, vitamin D supplements are generally inexpensive to buy. I doubt I’d ever get a prescription for one, they’d probably just tell me to pick some up at the pharmacy downstairs.

That will be why the doc tells you it's too expensive, because over the counter is cheap. It's not that they can't afford it, but in the UK there is a standard prescription price. It's under £10 per prescription for any drug that prescribed, but it's a flat fee. So if they prescribe something that costs less than the prescription charge it makes no sense for the patient.

There's a standard perscription price in England, not the UK. in Scotland and Wales there's 0 charges to the patient

Thanks for the correction.

I found that taking a specific brand of Vitamin D (the Genestra D-mulsion in particular) right before bed was guaranteed to give me vivid dreams. I've had half a dozen friends try it, with every single one reporting similar results.

That's interesting. I know vitamin D can improve sleep quality in people who are deficient, and sleep quality helps with dream recall -- I wonder if that's the mechanism or it's something else.

A cursory search shows lots of redditors taking Vitamin D (some of them way, way too much btw) and having wild dreams too.

I take 800IU a day and haven't noticed anything on that little.

That is actually a low dose.

Yeah, I showed a really mild deficiency in my work so they just suggested adding a low daily dose for me. I wouldn't expect to have had any side effects.

I was very deficient and they gave me 50k UI per day prescription vitamin D3 for 60 days. Sure enough I was high-normal on my next test. 800ui is likely not enough to have any effect unless you consistently take it for years.

That's wild. I've never heard of such a high dose being prescribed daily.

Yes, I wouldn't expect to notice anything on my dose.

It was for 60 days. If they continued to take this much indefinitely it would surely cause troubles, but 60 days when starting from deep deficiency is reasonable.

I was very very low, googling my level 'risk of rickets' came up!

Even that sounds extreme. The "Vitamin D Hammer" for people extremely deficient is 50k IU just once, not even for a temporary period.

It is high, but it's not extreme. 50k IU just once is an equivalent of about 7000 IU daily for a week, which won't really move the needle much if you're seriously deficient (in fact, it's still within what's considered a safe daily dose for healthy people - you can produce more than that from sunlight alone). You can feel free to take your "hammer" weekly, no deficiency required.

When I took >5000 IU daily for three months, I only raised 25(OH) D level in my blood from 9 to 30 ng/ml, and there's no evidence of toxicity below 150 ng/ml.

Of course, when dealing with high doses you need to keep your levels in check, as absorption can differ between individuals.

What is way too much? I take around 4000IU per day. Which just about brings my blood levels into the “green” area in blood testing.

FWIW: my functional provider recently noted low levels in my labs and I was already taking 2K IU daily. She bumped me up to 6K UI daily.

The reddit post was taking 50,000IU a day, which is usually the amount prescribed for someone to take once a week.

Your 4000IU isn't too much. Lots of the brands you see in stores are 5k for daily supplementation.

> Your 4000IU isn't too much.

By what metric? Jeez. People, you need to get your blood checked. There is no one-fits-all dosage. In winter, 4000 IU/d was enough to raise my blood levels well into the excessive range.

My 4000 units were after blood testing and also after genetic testing which showed some VDR mutations that might benefit from supplementation. As mentioned in another comment, that dose brings me slightly over 30 ng/ml, so basically borderline ok.

I fully agree that supplementation should always be combined with both blood testing and also a general medical evaluation.

4,000 is perfect.

Current recommendations are 800 IU per day if you’re not significantly deficient. Always keep testing at least once a year or so. I took 5000 IU per day for a while, which ended up pushing me over 60 ng/ml. That’s considered too high a level and may have negative health effects.

I tested after taking 4000 IU daily for quite a while and ended up at 30.9 ng/ml, so I guess I have some buffer left. But I fully agree, regular testing is prudent when supplementing anything above common established levels.

Given 10min of sunlight the body can naturally produce 15,000UI equivalent so I think gp is likely astroturfing for that brand

I've heard not to take vitamin D right before bed because it will kinda keep you up. Maybe the vitamin D as a stimulant is what's gives you the extra dream awareness.

I checked the ingredients. That is because it contains glycerin. Which is a great and safe supplement to take for anyone with sleeping issues. But will cause very vivid dreams at the start. D3 will not by itself have a huge effect on dreams.

This is such a weird fact that I googled it and sure enough it is widely noted!

my bottle of Nature Made D3 also contains glycerin

Probably common since there is pretty much all upside to supplementing it.

> Glycerin

Do you mean glycine? I've not heard of glycerine having a positive effect on sleep, although glycine is often recommended.

Glycine is an amino, glycerin is a triol.

When I tried to search specifically for "glycerin" and sleep I just get a couple of reddit threads, but no real sources.

Spicy food and dehydration do wonders for me!

Supplementing any "large" amount of either Vitamin D or Bs really messes with my sleep. It makes it harder to fall asleep and I get crazy dreams (and sometimes hallucinations in bed too)

I bought some and have not noticed any impact on my dreams.

>In fairness to researchers, it can be difficult to run a randomized clinical trial for vitamin D supplements. That’s because most of us get the bulk of our vitamin D from sunlight

And how hard is it to make such controlled studies on prison populations (where both sun and food intake is also a known value)? Make it voluntary and give some incentives for those wanting to participate. Can study supplement effects for one or even five years, it's not like they're going anywhere.

That's also a question I have when I hear about diet studies. What's easier than doing such in prison populations? Make it as voluntary as it's for people outside, and there's no ethical issue. We're talking like checking the effect of this or that food or diet style, which they can let different people chose their own. They already eat what they're given anyway, that would be an improvement.

> And how hard is it to make such controlled studies on prison populations (where both sun and food intake is also a known value)?

Very hard. Not impossible, but even something as low risk as a dietary study with Vitamin D supplements would come under very heavy scrutiny and likely be rejected.

Prisoners are considered a vulnerable group with diminished autonomy so there is no such thing as “voluntary as it's for people outside“ in prison. Full stop. The Nuremberg Code, Belmont Report, and Declaration of Helsinki all explicitly spell that out.

Even ignoring the obvious “ethical issues” that have been settled since the Nazis, they’re also legally protected. See 45 CFR 46 Subpart C [1]. Even if the experiment got past the academic ERBs, the HHS ones will likely shut it down.

[1] https://www.hhs.gov/ohrp/regulations-and-policy/regulations/...

"Putting the entire population on vitamin D supplements would be too expensive for the country’s national health service, he told me."

This seems absolutely bonkers. Vitamin D is dirt cheap, and if you can think at all beyond first-order effects, the improvement in immune health alone would likely pay for itself in terms of cost to the healthcare system.

I guess the logistics of prescribing an entire population of anything is expensive, and overkill when people can supplement it in pills or diet, or just go outside more.

"Go outside more" is absolutely a nonstarter in the places that most need this: northern latitudes in the winter.

Not only is "outside" often so cold that you need to cover enough of your skin that the sunlight would barely help, the weaker sun we get in winter just doesn't produce enough vitamin D in our bodies. That's the problem.

(Edit: "northern latitudes" can probably be replaced with "more extreme latitudes," as I believe there are some places that are far enough south that they also experience this, just at the opposite end of the year)

Which is why the Soviet government used “ultraviolet baths” to make sure that children up North got their vitamin D.

https://www.nationalgeographic.com/photo-of-the-day/photo/ul...

I solve this with 2 150w led corn lamps in my office!

A year of over the counter Vitamin D is around 30 pounds. (Not including bulk discounts or administrative/distribution costs)

The population is 70 million.

So 2.1 billion pounds, about 1% of the total NHS budget.

So do Vitamin D supplements reduce healthcare costs by at least 1%

1% if the NHS budget is one thing, and 1% of healthcare costs is quite another. They are orders of magnitude different.

Presumably they are equivalent.

Cutting one by that much also cuts the other.

I get mine (2000IU & K2) from Amazon where 400 tablets are between £8 and £10.

That is before any bulk discounts are considered.

VitD as a preventative would probably be distributed through the GP system rather than the hospital system, and so be procured locally and subject to the Drug Tariff system.

I think it would be great for this to be procured centrally for great discounts and dispensed locally exempt from our tariff guides and prescription charges. After all, the NHS has great clout as it employs 1.5M people and we spend > £300B on healthcare. But the NHS changes very slowly, mostly because it’s the ultimate political football and suggesting any change means the usual suspects screaming that you’re trying to destroy it. We’ll get to preventative medicine when we’ve tried everything else.

The amount of money lost treating sick people who now have renewed vigour to solve other problems in their life would be just too much

In the 1930s, the US starting fortifying milk with vitamin D in an effort to eradicate rickets, so it's definitely doable. Learned this after moving to Germany and realizing none of the milk here has any vitamin D added.

With so much of the UK with living with unspecified malaise, some significant part of which likely contributing to their low employment participation rate, I suspect giving everyone vitamin D would be very cost effective.

Idk I think most of it comes from the food

As a conversational point, I do recall reading an article sometime ago about people moving to the UK from sunnier places, and then suffering from Vitamin D deficiency!

Youll struggle to get the rda from diet alone unless you eat daily fish.

https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessiona...

Surely they meant that the malaise comes from the British food…

English food tends to be better at home than at restaurants. Also, it tends to mostly be undefined brown lumps but it does have flavor and there are some spices. (mostly mustard)

The exception is "Chinese takeaway", which is actually as bad as the stereotype.

Well there is a growing Indian population so that might skew the statistics on home cooking lol.

Anecdotally, by far the worst home cooking I’ve had was at the hands of a British couple; tasted like simmered dish water.

There's actually an Orwell essay about this.

https://www.orwellfoundation.com/the-orwell-foundation/orwel...

The thing I find odd about British restaurants is that all the Japanese chains (Wagamama, Itsu) have names that are so dumb it's like they're actively trying to be offensive.

I went to the doctor about eight months ago for an unrelated ailment, but the doctor wanted to do some blood tests. Turns out I had a fairly large vitamin d deficiency.

The doctor told me just to pick up some supplements. After a couple weeks I was genuinely surprised how much better I felt. Overall less lethargic. I've been feeling over all just kind of blegh for a long time and it really seems to have helped.

My dad had suggested vitamin d and I didn't take it seriously but he was right.

I know it’s not popular to comment about meta web annoyances, but holy shit, five popovers in a row!? One after another, like whack-a-mole?

I really want to meet the people that create these for money and ask them how much it hurt to have their ethics surgically removed.

I’ve talked to people that work at cigarette companies, online gambling, and worse. It’s always fascinating to hear their excuses.

I just used Safari's hide distracting items feature. Popovers gone.

I used the close tab button. Same effect.

>For me, that means topping up with a supplement. The UK government advises everyone in the country to take a 10-microgram vitamin D supplement over autumn and winter

My last blood test showed I was slightly deficient in vitamin D - my doctor recommended a 50 microgram (2000 IU) supplement. My next test to see how well it' working isn't for a few more months.

Get a metabolic test as well to check your calcium levels since D can increase serum calcium if you have genetics like mine.

It's frequently suggested that you take vitamin K2 with vitamin D, which helps direct calcium to the bones.

Yes, Salmon is also high in K2, but for me the calcitonin was more important. My D levels and calcium levels are great now.

Isn’t vague mixed evidence of a small, limited effect pretty much what you’d find if it it did basically nothing in aggregate?

This article aside, there are a number of very well established benefits of vitamin D. I think “mixed evidence of small limited effect” is not a phrase that is reflective of current knowledge.

No one will probably believe this, but I think dust mite exposure is a major cause of vitamin D deficiency and a lot of the negative outcomes associated with low vitamin D are actually second+ order effects of dust mite exposure. Just posting in case it reaches one person out of the 100s of millions who are sick from dust mites.

citation? There's many open to believing it and the reach maybe more if there are studies that confirm causation with a high probability.

fwiw - vit-d supplementation is one of the easiest supplements available. The recommended dosage 400IU is way lower than what can actually bring your levels up. You need about 4000IU of supplementation and regular testing if you're not exposed to sunlight and/or your dairy intake is poor.

I've read hundreds of dust mite studies, and this is the conclusion I came to, but it's difficult to put in a direct single argument with a citation that most people would require to accept it. I also got dust mites entirely out of my home and my chronically low vitamin D was resolved without a change in lifestyle or supplementation.

But I'll do my best to share some of the steps toward this conclusion:

#1. There is a body of molecular research showing dust mite allergens directly damage the immune system, most importantly once you inhale their fecal pods, they cause epithelial permeability in the lungs. (this study is a good overview of several ways it directly damages the immune system, all of which are totally unrelated to type 1 hypersensitivity, btw: https://www.jacionline.org/article/S0091-6749(18)30848-0/ful...)

#2. There are challenge studies that show dust mites directly causing eczema symptoms after inhalation, which shows that dust mite allergens can act on areas other than the respiratory system, probably by entering the blood stream. Of course there are also challenge studies for asthma. (here's a paper arguing for causal role in asthma https://www.atsjournals.org/doi/full/10.1164/rccm.200811-175...)

#3. All of the major allergic diseases(asthma, eczema, rhinitis, and although it is not as well studies, I believe IBS) have epithelial damage and increased allergy as a core feature of the disease. #1 and #2 are good evidence that dust mites play a causal role in these diseases

#4. From asthma and epithelial permeability in the lungs you can get to worse outcomes from flu and covid etc, from rhinitis you can get to worse sleep and worse mental health etc and reach a large number of health outcomes.

#5. It's true that people with allergy suffer worse from all these problems, but so much damage has already been done before you even get to Type 1 hypersensitivity, but that's another story.

So basically, dust mites directly damage your immune system in the lungs, skin, nose, eyes, guts(and maybe more?), create a sustained immune response, and leads to a multitude of other bad health outcomes.

And since low vitamin D is associated with dust mite sensitization((https://www.worldallergyorganizationjournal.org/article/S193...) , it's also associated with all those other bad health outcomes that are actually caused by dust mites.

People have a mental model that vitamins are at the root level of causality, and therefore don't consider that vitamin D could also be caused by dust mite exposure.

IgE levels are inversely associated with vitamin D: https://www.nature.com/articles/s41598-020-77968-1

But supplementing vitamin D doesn't lower IgE: https://publications.aap.org/pediatrics/article/150/Suppleme...

And of course high IgE is directly caused by exposure to dust mites if you're sensitized.

I don't know the specific mechanism by which they cause low vitamin d, but two possibilities are that #1: the high and sustained immune response your body runs from constant dust mite exposure consumes vitamin D and acts like a leaky bucket. #2: dust mites somehow disrupt vitamin d production in the skin(e.g. there was one study showing https://www.jacionline.org/article/S0091-6749(13)01768-5/ful...)

This helps. Thanks!

How did you get dust mites entirely out of your house?

Internet says to keep humidity below 50%, so a dehumidifier.

Basically a two step process: 1. Keep humidity at 40% year round, using dehumidifiers. This stops their biology and makes them go dormant quickly. Their eggs and protonymphs will die out after a year or so. 2. Remove existing allergens from your home. In short: allergen covers around your bed, get rid of old fabric stuff(curtains, rugs, carpet). Launder everything you can on the highest heat possible.

Any pointers on how to get rid of them from your house and sleep environment to lower ige?

I'm actually buying a D³+K²+magnesium combo (as both k2 and magnesium are recommended when taking d3) - just because it's pretty much the same as buying the d3+k2 combo.

Also h I chug it down with a solid portion of tran/cod liver oil. D3 is supposedly best ingested with fats.

A few months ago I felt incredibly depressed, demotivated and hopeless out of the blue. I was about to go to a psychiatrist to get some anti depressants but I just happened to get some bloodwork done. My vitamin d levels were super low at just 9. Few months of supplements got me to 35 and I've been feeling much better.

Good article, but it does not cover toxicity; you can take too much vitamin D and this has very negative affects. Usually a multivitamin is enough for supplementing; taking extra is where you can run into issues; consult your Doctor.

Evidence that multivitamin d is useful?

IIRC, toxicity is very rare even in very high doses (like 20 k IU a day) for weeks/ two or so months.

There was a study where participants had been consuming 10kiu per day for years without any toxicity.

I apologize if this sounds stupid but has the OP ever considered moving to a country like India during december and jan, wouldn't it solve the issue?

It's much, much more convenient to just visit a tanning bed once a week for 10 minutes.

During the Pan I took a lot of VitD. It started giving me the feeling that my heart was beating out of my chest, so I stopped.

How much Vitamin D? Vitamins are good but as with many things, the poison is in the dosage. You can definitely take too much of it.

After about a week of 1000 IU per day my chest started hurting and I could feel my heart anywhere in my body.

Vitamins A, D, E and K can be overdosed… But for vitamin D to be toxic you would have to veer quite far from the posology.

Is it necessary to take k2 along with d3?

Mushrooms exposed to UV convert egosterol to vitamin D - an almost identical mechanism found in our skin

I do not tolerate vitamin d supplements, they make me sick. Im actually switching to eating salmon and other fish in winter + getting the sperti vitamin d lamp.

I'm the same and I tolerate vegan D3 (from lichen). Some people are sensitive to the sheep-wool derived regular D3.

I will give it a try thanks for the suggestion

It's generally much easier and cheaper to just go to a tanning bed once a week, than buy your own Sperti "mini tanning bed". A full-size tanning bed will be much more even across your skin. Unless there are no tanning salons in your area.

They sell two different products one is for tanning, one is for vitamin d. I dont now if the total cost is cheaper (i dont think it is) but certainly seems a lot easier to have the lamp in my own home and not go anywhere for it.

>Putting the entire population on vitamin D supplements would be too expensive for the country’s national health service, he told me.

What? Have these people looked at what Vitamin D costs at the supermarket. If Vitamin D insufficiency has any significant detrimental effects, then 3 bucks of supplements a month surely are cheaper than dealing with the consequences.

If one hour of doctors time costs 200 bucks, then this is enough to pay for FIVE AND A HALF YEARS of Vitamin D supplements.

This seems like a completely insane statement.

We need sunlight prescriptions

I know a very dark african lady that was given that by her GP, she was waring indoors a lot and in winter was not getting enough sunlight.

How do you downvote garbage non-content like this?

Linking a molecule, that takes part in a complex cellular mechanism, with a general health outcome will never go well and is nonsense.

Fellow tech people forget hacking your body with innocent pills or having any meaningful effect without sacrifice. Kill your stress, maintain normal weight and have nice relations.

> At a checkup a few years ago, a doctor told me I was deficient in vitamin D. But he wouldn’t write me a prescription for supplements, simply because, as he put it, everyone in the UK is deficient. Putting the entire population on vitamin D supplements would be too expensive for the country’s national health service, he told me.

Ugh. It's amazing how incompetent medical systems are. I was also deficient in vitamin D and my doctor wrote a prescription. When I did the math, the cost was something like >$.10 per 1000IU. But if I bought the vitamins from a normal store, I would pay <$.01 per 1000IU. Since a person lacking sunlight only needs 1000IU, the price for giving everyone in the UK Vitamin D would be <$700k/day. And probably much less since most people won't need this high of a dose and bulk quantities would be cheaper.

For healthy people, taking extra vitamins is pointless, but giving them to people who are deficient in vitamins is one of the cheapest health interventions for the benefits.

PSA: if you're feeling off, make sure your doctor checks your various vitamin levels and see if cheap OTC vitamins help.

Too add to this, if anyone is considering looking for otc vitamin supplementation, please check to see if the brand you're interested in has been lab tested. Heavy metals have been found in cheap stuff before in the US and the government isn't really screening for this stuff proactively.

If you consider the deficiency a national health issue, you can even subsidize a nation scale production reducing the cost even more. From a state perspective, that should be chump change considering the nation-wide effects.

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