[HN Gopher] Vitamin D reduces incidence and duration of colds in...
___________________________________________________________________
Vitamin D reduces incidence and duration of colds in those with low
levels
Author : cachecrab
Score : 286 points
Date : 2025-10-28 13:31 UTC (9 hours ago)
(HTM) web link (ijmpr.in)
(TXT) w3m dump (ijmpr.in)
| AbstractH24 wrote:
| Newsflash: When you are sick, addressing comorbid conditions
| helps you get better faster.
| InsideOutSanta wrote:
| Yeah, this is a crucial point. This is studying "adults with
| suboptimal baseline." If you have a vitamin deficiency and get
| sick, I would expect supplementation with that vitamin to
| provide some relief, regardless of which vitamin it is.
|
| This does not mean that the same will happen for people who did
| not have a deficiency.
|
| Having said that, there is good evidence that Vitamin D
| deficiency is widespread, and supplementation of Vitamin D is
| relatively safe unless you take excessive amounts.
| kacesensitive wrote:
| Anecdotal but when I'm sick I double my vit C and D intake which
| typically helps me.
| pif wrote:
| > which typically helps me.
|
| Uhm, how can you get to that conclusion? I mean: how can you
| compare the evolution of a cold with and without the vitamin
| surplus?
| kacesensitive wrote:
| Very well could be a placebo
| btilly wrote:
| Reminds me of the old, with treatment, most colds will be
| cured in just 7 days! Without treatment they generally last
| about a week.
|
| That said, do not underestimate the health benefits of the
| placebo effect. It can help a lot. Particularly with
| anything to do with stress.
| IAmBroom wrote:
| So your statement should have been, "it seems to help."
| garciasn wrote:
| IANAMD.
|
| It is my general understanding that unless you are severely
| deficient, Vitamin D supplementation generally takes weeks to
| bring levels up. It's unlikely that taking it for a few days is
| going to have any measurable impact on your recovery from
| illness unless you are severely deficient and/or taking MASSIVE
| doses, which may or may not be recommended depending on your
| prior levels and BMI.
|
| See more here: https://www.ccjm.org/content/89/3/154
|
| e: fixed broken URL
| kacesensitive wrote:
| Very interesting thanks for sharing!
| supportengineer wrote:
| Same... In our family we start taking Emergen-C a few days
| before we travel also.
| driverdan wrote:
| Which is very overpriced and doesn't do anything unless
| you're deficient. Excess vitamin C does nothing, it goes
| right through you.
| thrusong wrote:
| I live in Winnipeg, Manitoba where it is quite cold for a big
| majority of the year. I have dabbled with supplements because I
| get a couple of major colds every year.
|
| I've heard things like you only need 15 minutes of sunshine per
| day to get your recommended dose of Vitamin D, but I've also
| heard it can be quite bad for you if you have too much in your
| system (and it's hard for your body to flush excess amounts).
|
| If there a safe level of Vitamin D supplements where you won't
| run this risk? I don't drink milk either because I'm lactose
| intolerant.
| mwigdahl wrote:
| I take 5000 IU per day year round and have not had any issues.
| Research suggests you can dose 10x that without major problems,
| although personally I wouldn't go higher than I am already.
|
| https://pubmed.ncbi.nlm.nih.gov/30611908/
| toomuchtodo wrote:
| Vitamin D toxicity is a legitimate concern, so those dosing
| should be mindful of it, depending on dosage and existing
| serum levels. Don't action on medical advice from strangers
| on the internet alone, talk to you doctor or other
| credentialed medical practitioner you work with if needed.
|
| https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu.
| ..
| ErikCorry wrote:
| That sounds like a lot:
|
| _To help prevent vitamin D toxicity, don 't take more than
| 4,000 international units (IU) a day of vitamin D unless your
| healthcare professional tells you to. Most adults need only
| 600 IU of vitamin D a day_
| https://www.mayoclinic.org/healthy-lifestyle/nutrition-
| and-h...
| scythe wrote:
| Part of the issue with vitamin supplements is that the
| bioavailability can be unpredictable. The actual amount
| absorbed can vary between 10% and 100% depending on the
| time of day, supplement formulation, what foods if any are
| taken together, as well as the particular characteristics
| of the individual's intestines, which are difficult to
| assess. Because supplements are not regulated as
| pharmaceuticals in the United States, this variability can
| be severe; in the worst cases, supplements do not even
| contain the active principle.
|
| So, I am not surprised that someone needs to take 5000 IU
| to get 600 IU worth of effect. Institutional medical
| authorities are (rationally) quite defensive when
| cautioning readers about supplement consumption; they must
| consider the worst case (100% bioavailability) when
| assessing the risk of overdose.
|
| As an alternative to vitamin supplements, exposing common
| dietary mushrooms to ultraviolet light converts (by an
| uncatalysed photochemical reaction) the ergosterol therein
| to calciferol. How best to achieve this in a home setting
| is unclear.
| morley wrote:
| One number is not going to work for everyone. The only way
| to be sure is to get a blood test for Vitamin D levels. I
| get tested with my yearly physical, but if someone really
| cares they can get more frequent blood tests.
| mwigdahl wrote:
| The advice on this is all over the map and that's a big
| problem in the space. Reputable medical sources have
| recommendations almost two orders of magnitude off from
| each other at times.
|
| This article, for example:
|
| https://www.ccjm.org/content/89/3/154
|
| ...cites several cases where daily supplementation of 50K
| IU was required to restore normal D levels, although also a
| case where that same dose caused toxicity. As one of the
| other commenters in the thread noted, working with your
| doctor to establish the right level is probably the right
| move. If nothing else, they have the capability to test
| your serum levels to see where you're at.
| shmel wrote:
| You can't possibly have the same recommendation for all
| geographies. Florida and Scotland have somewhat different
| level of UVB especially throughout the winter, come on.
| cgh wrote:
| I experimented with taking 10,000 IU a day for about a
| year. I had my D levels checked with my normal yearly blood
| test (lipids, etc) and it put me into the high normal
| range. I still take 5000 IU daily and have for years with
| no ill effects.
|
| I should note that I live in a place that sees little sun
| for five or so months a year.
| LocalPCGuy wrote:
| As has been commented elsewhere, everyone absorbs vitamin D
| differently, this really is a matter where someone should
| just get tested, if they (and their doctor) decide
| supplementation is needed, do so, test again, and adjust
| dosage accordingly until desired levels are attained.
|
| Not medical advice here, but harmful effects from vitamin D
| exposure/toxicity generally only happen at very high
| levels, or if high doses are taken over long periods of
| time (as excess can be stored in fatty tissue/liver).
| Doctors often prescribe a very high dose (like 50,000 IUs)
| for individuals who are very deficient (often taken once a
| week, not daily) for a short period before going on a more
| standard (400-2,000, maybe 5,000) IU dose for maintenance.
| lisbbb wrote:
| It's bad for your kidneys
| BurningFrog wrote:
| It's _possible_ to overdose on Vitamin D, but you have to eat
| absurd amounts.
|
| Unless you eat the pills like candy, you're safe.
| hollerith wrote:
| Untrue. Source: painful personal experience.
| amanaplanacanal wrote:
| How much were you taking?
| hollerith wrote:
| I don't remember because it was 25 years ago. Not a huge
| amount.
| pelzatessa wrote:
| I take 8000 D3 (+200ug K2 MK7) daily and I'm fine. since
| covid I go like this for entirety of winter and then back
| down when summer comes. Perhaps you live in a climate
| where you get a lot of sun exposure and somehow overdosed
| on that. A guy from vitadmindwiki.com even says that
| you'd have to take 14000IU daily for a year until
| reaching toxicity limit (although this guy tends to
| sometimes say different things on the same topic, so I'd
| be cautious on whether this is the exact amount)
| https://vitamindwiki.com/Overview+Toxicity+of+vitamin+D
|
| Although it'd be great if you explained what exactly
| happened, perhaps it wasn't a result of taking vitamin D
| itself but rather some external thing. Judging by
| "painful experience" I assume kidney stones, which could
| be caused by too much calcium or genetic preference. not
| a doctor or an expert on the topic though, just open for
| a discussion :)
| hollerith wrote:
| The symptoms are hard to describe (but did not include
| kidney stones), but it was obvious that something was
| drastically wrong and the drastic wrongness went away in
| response to my completely avoiding all sunlight and
| dietary sources of vitamin D and my doing a few other
| things described below.
|
| Most people could probably take as much supplemental
| vitamin D as I did without incurring this adverse effect,
| but there is no straightforward way for a person to know
| whether they are in the minority of people who will incur
| the effect. (I do remember that having Northern European
| ancestry makes the effect more likely.)
|
| The drastic wrongness started showing up after only a few
| months of whatever high dose of D I was taking (and I
| regret that I cannot provide this information: I did
| search for it briefly; but it was definitely not an
| "absurd amount") so if you've been taking the 8000 D3 for
| years, then the drastic wrongness is unlikely to suddenly
| show up in your case -- and if it does show up it would
| probably be because you contracted some sort of chronic
| infection.
|
| The presence of certain kinds of chronic infections and
| genetics are the main causative factors according to the
| information I relied on 25 years ago. Actually, here is
| the basic information. I followed most aspects of the
| protocol including my obtaining a prescription for
| olmesartan, but then I lost interest when the drastic
| wrongness went away (after not much longer than 4 months
| IIRC). I was also probably on an antibiotic during this
| recovery.
|
| https://mpkb.org/home/patients/protocol_overview
|
| P.S., I take as much MK7 as you do (i.e., twice as much
| as the "suggested usage" on the label) and have for many
| years, just without supplemental vitamin D.
| pelzatessa wrote:
| Most interesting, will bear that in mind. To this date I
| haven't encountered any "drastically wrong" symptoms with
| my d3 usage and frankly haven't heard that much about any
| adverse events linked to vitamin d3. If you feel
| comfortable with that then you could disclose what
| exactly is that adverse effect you've been experiencing,
| but I see that you try to avoid this topic so no pressure
| :)
| hollerith wrote:
| It's not that I'm unwilling to publish the information:
| it is just that I despair of putting into words how I
| knew something was drastically wrong with my physiology
| -- especially now that 25 years have gone by.
| LocalPCGuy wrote:
| Generally agree, but unlike water-soluable vitamins, vitamin
| D can store excess in fatty tissue and the liver, and so if a
| person takes a large dose (generally 10,000 IU daily or
| more), they could develop toxicity over time due to the
| build-up. That's why it's important to test and adjust
| dosages according to the data.
| efsavage wrote:
| You probably have to really try to take too much Vitamin D with
| any over the counter supplement (<=5,000 IU), especially if you
| live that far north. For reference, a prescription dose for
| someone who is low is usually 50,000 daily.
|
| It should be part of your standard blood tests so you should
| know if you're running high or low and your doctor can
| recommend or prescribe a good dose.
| colechristensen wrote:
| With 5,000 IU sometimes taking several at a time I had blood
| levels of Vitamin D at the top of the range which wasn't
| _dangerous_ it was just informative, "hey you're having
| enough, tone it down".
| gilfoy wrote:
| I've had a prescription twice and it was 50,000IU of D2 once
| weekly. Usually the OTC one people buy is D3.
| more_corn wrote:
| If you dry your mushroom the sun they generate a crap-ton
| of d2. There was a study earlier this year.
| BeetleB wrote:
| It's 50,000 weekly.
| bluGill wrote:
| I've heard the 15 minutes is all you need. I've also heard that
| in winter the sun is so weak that no amount of sunshine gives
| you any. (even if you were naked outside in winter - risking
| frostbite).
|
| I'm not a medical doctor. I cannot evaluate any of the above
| claims. I wish I could find a source I could trust.
| thewebguyd wrote:
| Depends on where you are. Latitudes above roughly 35 degrees
| N, the sun is too low in the sky roughly between October and
| March to allow for UV-B rays to penetrate, which is what your
| skin needs to synthesize vitamin D.
|
| So yes, if you live in the northern regions, you don't
| produce any at all from sun exposure, even on a bright sunny
| day, during most of the year.
|
| Up here in the PNW, even in the summer, you only have a
| window of roughly 4 to 5 hours where the sun is high enough,
| in July.
| snozolli wrote:
| _I 've heard things like you only need 15 minutes of sunshine
| per day to get your recommended dose of Vitamin D_
|
| The figure I read years ago was that it takes 15 minutes _in
| short sleeves_ to get the necessary light exposure at the 45th
| parallel in winter. I 'm right at the 45th parallel and I don't
| go out in short sleeves in the winter, so I imagine it's
| significantly worse for you!
| jerf wrote:
| "Winnipeg, Manitoba" ... "only need 15 minutes of sunshine per
| day to get your recommended dose of Vitamin D"
|
| That doesn't apply to you most of the time, unfortunately.
| Vitamin D is the result of UVB exposure. For significant
| portions of the year, you don't get very much [1], compare
| with, say, [2] Orlando Florida in the US. 10-15 minutes is for
| a UV index of 7 [3], so that's only 4-6 months out of the year
| for you. And just based on my couple minutes with Google here,
| that number may also include the assumption that you're not
| just "out in the sun" for 15 minutes, but basically sunbathing.
| Lesser exposure may take longer: [4] Winter times can be
| effectively impossible because you can't sunbathe at 10 below
| (regardless of which scale I'm talking about) and you're not
| going to spend the requisite hours in the sun for what little
| skin is exposed. Or they can be outright impossible if your
| skin is dark enough.
|
| [1]: https://winnipeg.weatherstats.ca/charts/forecast_uv-
| monthly....
|
| [2]: https://nomadseason.com/uv-index/united-
| states/florida/orlan...
|
| [3]: https://overcomingms.org/program/sunlight-vitamin-d/uv-
| index...
|
| [4]: https://vitamindwiki.com/dl2105?display
| soperj wrote:
| I grew up on the Canadian praries. -10C is basically shorts
| weather.
|
| edit: seriously though, anything warmer than -10C you'll
| definitely see kids in shorts. I go skiing in shorts every
| year.
| zdragnar wrote:
| I'm not sure that people downvoting you have been around
| northerners much. Down here in the upper midwest US, we
| tend to consider 4 or 5C to be shorts weather in the
| spring. I've a friend who would wear flip flops / sandals
| outside down to roughly -10C.
|
| Then again, most people aren't getting the equivalent of 15
| minutes of index 7 UVB exposure at those temperatures, so
| it's not quite the same thing, but still.
| ikamm wrote:
| People are downvoting because it has nothing to do with
| the comment they're replying to or the original post.
| Most people are well aware temperature is relative too, I
| live in the American South and there are certainly people
| here who will wear shorts in cold or freezing weather
| too.
| soperj wrote:
| > Winter times can be effectively impossible because you
| can't sunbathe at 10 below
| IAmBroom wrote:
| Wear a g-string if you want. It doesn't make the sunlight
| any brighter in winter.
| pavel_lishin wrote:
| But it does expose more skin, which [3] recommends!
|
| Sadly, it doesn't say how long you should exposure
| yourself with a UV index of 1, which is what Winnipeg has
| _today_ , and it's not even proper winter yet.
| milesvp wrote:
| First know that the body will stop making vitamin D before you
| reach overdose quantities. This means you should take vitamin D
| in the morning.m rather than the evening. Second know that
| vitamin D is fat soluble. So if you are losing weight, you can
| more easily overdose if you have high levels stored in your
| fat. Also know the body won't absorb as much vitamin D if you
| don't take it with fat.
|
| This can make dosing tricky. You can be taking an amount that
| is safe right now, but then is too much later.
|
| You can max out your body's vitamin D production even on a
| cloudy day, though the sun's angle of incidence effects
| production.
|
| The body typically maxes production at something like 20k iu
| (pleae verify this number it has been a while since I learned
| it), so staying below this number should mostly safe.
|
| The USDA has set its recommended daily allowance mostly to
| avoid rickets. It is largely considered too low a number for
| general well being.
|
| I live in north western Washington, and previously used to
| combat seasonal affective disorder, with some pretty dark
| thoughts come february. Since I started taking 1k D3 some 20
| years ago much of the seasonal mental health has gone away. I
| take 2k D3 consistently currently, and if I run out for more
| than a week my mood starts to deteriorate quickly. I still
| haven't proved causation since there are likely reasons I've
| let myself run out of the supplement that long, but it is so
| consistent that I treat it as causal at this point. YMMV
|
| Please do research above just asking a forum for dosing advice
| though. This is a well educated place, and I would very much
| trust it as a starting point, but there is a lot of good
| published content on the topic. Though, I admit google is so
| bad today, I might fail to find any of the content I referenced
| years ago... if you use chatgpt make sure to require
| references, and check them. I find that using multiple
| instances to review research references separately prevents
| some context based poisoning as well. And pointing out
| inconsistencies can be a good way to find nuance in a topic.
| Though sometimes LLM will just waffle, and the context may be
| done
| dooglius wrote:
| You can get blood tests pretty cheaply. The safe level is the
| level that, after you take it consistently, has you in the
| desired range on the test.
| slow_typist wrote:
| EU considers 600 I.U. per day as safe. Probably not enough if
| the level is low. Blood sampling is cheap, why don't you have
| it checked.
| Etheryte wrote:
| You don't need to guess, go to your GP and get yourself tested.
| It's not expensive, depending on where you're from it might
| even be free, and usually you get the results back already the
| next day.
| humanfromearth9 wrote:
| 25000 IU weekly during winter is OK, for an adult
| a3w wrote:
| An adult with 60 kg or 160 kg of mass?
| zemvpferreira wrote:
| Heliotherapy is well-due for a resurgence. One of my favourite
| youtubers (conquer aging or die trying) has a great interview
| with a medical doctor about sunlight as a medical intervention.
| Well worth the watch:
|
| https://m.youtube.com/watch?v=UF8UE6cJaWQ
| dlcarrier wrote:
| That's Doctor Roger Seheult, MD, who hosts videos for
| continuing education provider MedCram
| (https://www.medcram.com/). They post lots of free videos on
| their YouTUbe channel (https://www.youtube.com/channel/UCG-
| iSMVtWbbwDDXgXXypARQ) and several of them cover the research
| behind heliotherapy.
| ErikCorry wrote:
| Most vitamins are a waste of time and money, some are even
| harmful[1], but there are a lot of people with D deficiency,
| especially in winter[2].
|
| 1 https://www.mdpi.com/2072-6643/17/17/2744#:~:text=highest%20...
|
| 2 https://www.abs.gov.au/articles/vitamin-d#edit-group-image--...
| layer8 wrote:
| Vitamin D isn't technically a vitamin in the strict sense,
| because unlike the other vitamins the human body can produce it
| itself (by exposure to sunlight).
| slow_typist wrote:
| Dogs can synthesise vitamin C...
| delecti wrote:
| And humans aren't dogs.
| wongarsu wrote:
| Most definitions of the word vitamin are not specific to
| humans. Wikipedia talks about "organisms", Britannica
| about "higher animal life", Webster about "most animals
| and some plants"
| lxgr wrote:
| What is and isn't a vitamin by definition varies from
| species to species.
| Aldipower wrote:
| Wow, that is interesting. They can synthesise it in their
| liver?
| bluGill wrote:
| Many animals can. There are a gene for it, humans don't
| have it. There is a lot of speculation as to why, but
| nothing really stands out (possibly just random chance -
| if you eat enough there is no advantage to keeping the
| gene and in turn no loss from losing it. However I'm
| unable to rule out other possibilities)
| https://pmc.ncbi.nlm.nih.gov/articles/PMC3145266/ is a
| really interesting survey of the issue across many
| different species.
| schuyler2d wrote:
| From the article: > Another argument supporting the
| suggestion that species which have lost their GLO gene
| were under no selective pressure to keep it, is that all
| species which have lost their GLO gene have very
| different diets but all of them have diets rich in
| vitamin C
|
| What would a diet poor in vitamin C be considering that
| "everything else" makes it? I guess root vegetables? It
| feels like, if anything, this would imply a GLO gene
| decay more often than has happened, no?
| bluGill wrote:
| That is probably a question for a nutritionist not me. My
| understanding is Grains, root vegetables, and meat are
| all low in vitamin C. Likely other things as well. But
| I'm not a nutritionist (I've read enough that I think I'm
| right here, but not enough to state it with confidence),
| so take the above with plenty of salt.
| lxgr wrote:
| Sure, many things are vitamins for one species but not
| another. (In fact, every vitamin must be able to be
| produced by at least one species - where else would it come
| from?)
| rhdunn wrote:
| The body can also synthesize vitamin A from beta-carotene
| which is effectively two vitamin A molecules joined together
| (one rotated 180deg relative to the other).
| jghn wrote:
| The issue I've found with these discussions is it appears
| there's mixed evidence on if vitamin D *supplementation*
| actually has a positive impact, regardless of vitamin D
| deficiency. In other words, is the deficiency causal or
| correlative.
|
| I have no opinion on the matter, and am inclined to think there
| is at least some positive benefit. But YMMV
| theshrike79 wrote:
| The problem is that vitamin D doesn't absorb the same way for
| everyone.
|
| If a 100 people take 50IU of Vitamin D, you get 100 different
| results.
|
| Some get enough from minor sun exposure and maybe eating a
| fish now and then. Others need massive doses to get any
| results.
| LocalPCGuy wrote:
| Echo this with a PSA: it's a simple test to get your
| levels, and I'm a proponent of ensuring it's included when
| you have other regular blood tests (may have to ask for
| it). That can allow a person to see patterns, how effective
| any supplementation (and different amounts) are, etc.
| johnisgood wrote:
| 50 IU is nothing. 3000 IU is something. I have MS, so I
| need to supplement at least 10k IU.
|
| And yeah, it does not absorb well unless you eat some fat.
| cj wrote:
| I took 10k iu via a multivitamin for a few months, and
| ended up with Vitamin D levels 5x higher than the maximum
| on the labcorp reference range. "Vitamin D toxicity"
|
| It took many months to get the levels back to normal.
| Vitamin D is one of those things that once you overdose,
| it takes many months for the levels to slowly come down
| after you stop supplementing.
|
| Be careful with Vitamin D!
|
| The downside to having high levels is plaque/calcium
| deposits in arteries, if I'm not mistaken. Which can be
| mitigated by taking K2.
| johnisgood wrote:
| Yeah, you should take vitamin D with K2 at the very
| least.
|
| Thanks for the tip though. I do not take it regularly so
| I think I'm fine. :D
| zahlman wrote:
| > An excess of vitamin D causes abnormally high blood
| concentrations of calcium, which can cause
| overcalcification of soft tissues, including arteries and
| kidneys. Symptoms appear several months after excessive
| doses of vitamin D are administered. A mutation of the
| CYP24A1 gene can lead to a reduction in the degradation
| of vitamin D and thus to vitamin toxicity without high
| oral intake (see Vitamin D SS Excess).
|
| > Treatment
|
| > In almost every case, ceasing vitamin D intake,
| combined with a low-calcium diet and corticosteroid
| drugs, will allow for a full recovery within a month.
| Bisphosphonate drugs (which inhibit bone resorption) can
| also be administered.[2]
|
| Regardless, blood levels need to be checked for this sort
| of thing and doses are not one-size-fits-all. I also once
| was taking 10k daily, for several months, and ended up
| just barely in excess territory with no noticeable
| symptoms. (I settled on taking 4k daily in the long
| term.)
| johnisgood wrote:
| > An excess of vitamin D causes abnormally high blood
| concentrations of calcium
|
| That is what supplementing K2 with D3 is for, too.
| cj wrote:
| > In almost every case, ceasing vitamin D intake,
| combined with a low-calcium diet and corticosteroid
| drugs, will allow for a full recovery within a month.
|
| Surprised to see just 4 weeks for a recovery. I got
| retested after 8 weeks (only minor improvement) and
| wasn't until 16 weeks until the test finally came back in
| range.
|
| 100% no dose is one-size-fits-all. I overdosed from
| taking a specialty multivitamin (it has a discord channel
| and everything). So was chatting with people taking the
| same vitamin, same dosages, also getting tested, but
| others had no issues at the same doses.
|
| I guess I just absorb vitamin D with great efficiency,
| who knows.
| 0xbadcafebee wrote:
| Are you aware of the history of setting acceptable levels
| of Vitamin D? Basically, 100 years ago, people
| experimented with cures for TB by giving patients one to
| two orders of magnitude higher dosage than the "vitamin D
| toxicity" levels reported today. Like insanely high
| numbers. Strangely enough, most people did recover from
| the TB, but they kept getting the treatments anyway, and
| that in a few instances led to bone issues. So for some
| reason that doesn't seem to be documented, they set the
| "safe level" of vitamin D to be something like two orders
| of magnitude lower than the level that actually caused
| issues. And that level has never been changed.
|
| All of the studies I've seen around Vitamin D
| supplementation has shown that the "safe level" reported
| today is way, way lower than it should be. People appear
| to be just fine taking 10k IUs for months on end, even 7
| years in one study. I think what we're learning is that
| the "safe level" is a very wide spectrum; some people
| could possibly be harmed from a low level, whereas some
| people are perfectly fine at a very high level.
| johnisgood wrote:
| Yes, and many people are fine with 10k IU for months
| because their body just does not absorb it well.
|
| And some people, like those with MS (such as I) need to
| take more than usual. Someone I know has MS and takes 20k
| IU and gets regularly tested.
| Etheryte wrote:
| 50IU is a minuscule dose though, no? If people are
| recommended to supplement, they generally take a dose in
| the range of a few thousand.
| swalsh wrote:
| i'm guessing he meant 50k not 50. 50k is quite a large
| dose.
| Etheryte wrote:
| There is no way that's what they meant. 50k is an
| absurdly large dose that's way outside the safe intake
| range. 10k is used sometimes under medical supervision
| and even then it's a very short term measure. For long
| term intake, 4000IU is a widely accepted safe upper
| limit. 50k is an order of magnitude more than that.
| hinkley wrote:
| If your doctor is not seeing results they'll keep upping
| the dose and I've heard of some that sound like an attempt
| at assisted suicide. Most of us would get toxicity from
| some of the ones I've heard.
| jaggederest wrote:
| My family is in this group. We are poor absorbers of
| vitamin D, some of my elder relatives need 5 times the
| "safe upper limit" to have healthy blood levels. As long
| as you're checking your blood values routinely (and for
| both D2 and D3, not just one or the other), it's
| reasonably safe. Sort of like other prescriptions in
| general.
| hinkley wrote:
| I heard about a guy who ordered a bottle and ended up
| with vitamin D poisoning, on one of those Ira Glass style
| podcasts. Turns out they forgot to compound it before
| sending it out so he was getting "cask strength" vitamin
| D. Sounded very unpleasant.
| detinho wrote:
| I can use myself as an example: I have crohn's disease and
| I can take doses of 50000UI for some weeks, then 4000UI
| daily and after a year have my Vitamin D results as low as
| 20ng/ml.
| LocalPCGuy wrote:
| Just my results (n=1) and I don't think this is exactly what
| you were saying, but just in case other read it the same way
| I did at first: having had (lab tested) vitamin D
| deficiencies, vitamin D supplementation can help to restore
| levels back into the desired range. So supplementation can
| have the desired effect of improving vitamin D levels (more
| below). It is a simple test that most doctors don't quibble
| about adding on to other blood tests (i.e. during annual
| checkup, for instance), but isn't generally checked by
| default. (note: insurers may want it to be "diagnostic"
| rather than "preventative" in order to cover the test.)
|
| Whether it has a "positive impact" on overall health (which I
| believe to be your point), that would be even more anecdotal
| and also impossible for me to narrow down whether that one
| factor had any significant effect, so I won't posit that. And
| I agree that from different studies I've read, the actual
| science on it is pretty varied and I haven't seen anything
| conclusive. Even this study notes their conclusion was "...
| among adults with suboptimal baseline vitamin D levels".
| nradov wrote:
| Most of the vitamin D supplement studies have been very low
| quality in that they give all subjects in each group a fixed
| amount (or placebo). Ideally they should periodically test
| blood levels and titrate the dose to hit a target range. This
| would get us closer to establishing causality (or lack
| thereof) including a response curve. The amount needed to hit
| a given target will be wildly different for many individuals
| based on factors that are still not well understood.
| mwigdahl wrote:
| This is solely my own anecdote, but I used to get bad
| seasonal depression every winter. I tried a number of
| interventions short of medication; none moved the needle very
| much. I started supplementing with vitamin D probably 8 years
| ago and haven't had any issues with seasonal depression
| since.
|
| I'm pretty personally convinced that it was the supplements
| that helped here.
| MisterPea wrote:
| I tried a 1000 IU vitamin D pills to no avail. Bumped it up
| to 5000 IU and still saw very marginal bumps in my blood
| tests
|
| I think I might try daily 10000IU after showing my doctor
| how little it's moving the needle for me
| benregenspan wrote:
| It's expensive in the US because one company has
| exclusive sales here (patent protection?), but you could
| try calcefidiol, weekly dose and is supposed to get
| levels up rapidly. Apparently it's the common form to
| take in Spain, and it's further down the metabolic
| pathway vs cholecalciferol. (I take but still have to get
| levels checked)
| MisterPea wrote:
| thank you, will have to check this out
| leetrout wrote:
| I was put on prescription vitamin D2 50000 IU and it
| caused a bunch of side effects for me including heart
| palpitations for over a week and then a paradoxical
| reaction to magnesium causing them to be even more
| intense.
|
| Proceed with caution and listen to your body. Doctors
| were accusing every other thing than accepting whatever
| it did to my calcium / other electrolytes bothered my
| heart.
| MisterPea wrote:
| Interesting, my levels have always been chronically low
| and I feel no effects from daily 5000IU
| leetrout wrote:
| That's still 15000 IU under my weekly dose so maybe you
| just haven't hit the threshold I hit.
| swalsh wrote:
| I can tell you supplementation works 100%.
|
| I took a blood test several weeks ago, my Vitamin D level was
| 14 ng/ml. I was so fatigued there were times I had to lay on
| my office floor because I didn't even have the energy to sit
| in my chair. I started taking 50k IU's weekly and then 10k
| IU's daily, and the results were dramatic. I went from having
| 0 energy to nearly normal. I also had soreness in my legs
| which went away.
| bluSCALE4 wrote:
| I don't agree. As with everything, it requires care. Taking a
| multivitamin and thinking you're good to go is delusional.
| bluGill wrote:
| For most people just eating a good balanced diet and they are
| good to go. There are a few with genetic/biological issues
| and they need more - ask your doctor. Vitamin D is one that
| modern lifestyles likely don't get enough of and so probably
| worth it - again talk to your doctor.
| bluSCALE4 wrote:
| If eating a "good balanced diet" were easy/normal, we'd
| have close to zero disease. Supplements are definitely a
| way to get as close as possible to balance when day to day
| food intake is chaotic.
| bluGill wrote:
| there is no reason to think a good diet will prevent
| disease, nor that supplements will help in most cases.
| Good diet will prevent some disease, but disease is
| natural in the environment and good diet is mostly your
| immune system has what it needs to fight it off after you
| get it.
| OutOfHere wrote:
| People like ErikCorry will get you to suffer greatly and then
| get you killed with their extremely harmful disinformation.
| Most doctors are no better in this way, although some are.
| supportengineer wrote:
| How do you feel about vaccines and Tylenol?
| IAmBroom wrote:
| Uncalled for. GP is pointing out that the fact the human body
| _can_ produce Vitamin D means it is _not_ a vitamin.
|
| vi*ta*min /'vid@m@n/ noun any of a group of organic compounds
| which are essential for normal growth and nutrition and are
| required in small quantities in the diet _because they cannot
| be synthesized by the body_.
| derbOac wrote:
| Glad to see this study, seems decent, but for a different
| perspective there was a relatively recent meta-analysis on the
| effectiveness of Vitamin D for RIs that suggested no effect:
|
| https://www.thelancet.com/journals/landia/article/PIIS2213-8...
| pavon wrote:
| One significant difference in this study is that it focused on
| people with low baseline vitamin D (10-30 ng/mL 25(OH)D), and
| moderate intervention (2000 IU daily).
|
| The meta-analysis you posted did perform subgroup analysis on
| people with low baseline vitamin D (<25 ng/mL), but this
| included a wide range of intervention levels, 90% of which were
| <2000 IU daily equivalent. They also performed subgroup
| analysis on high intervention levels, but this included a wide
| range of baseline vitamin D, 90% of which were >25 ng/mL.
| colechristensen wrote:
| And also there's a difference between infection incidence,
| intensity, and duration, the evidence I've seen has been
| strongest in reducing intensity and duration. Also dosage
| might just be too low.
|
| I've been feeling a little off lately with some respiratory
| symptoms and took 25,000 IU of Vitamin D, in people who are
| deficient (probably me lately) 400-1000 daily dose might not
| actually do enough to have an effect.
|
| It's about time for a meta-meta analysis comparing the traits
| of the different sets of papers (N, dosage, deficiency
| status, time of year, duration/incidence/intensity, etc)
| unionjack22 wrote:
| Vitamin D, red light therapy, insulin attenuating response of a
| walk, immunological benefit of allergen exposure, cognitive noise
| reduction and rest response of walks in forests.
|
| Man keeps trying to bring the outdoors inside.
| nickff wrote:
| While I find your comment enjoyably pithy, in the case of
| vitamin D, many humans are currently living at latitudes which
| they are not suited to (skin being too dark to generate enough
| vitamin D given the insolation), and eating diets which do not
| provide them with sufficient amounts of it (the carnivore diets
| of Inuits and similar groups being a good contrast).
| djtango wrote:
| Amusing how thanks to the war on cholesterol the UK
| unravelled a lot of egg eating habits - a natural source of
| vitamin D.
|
| The UK also consumed a lot more liver than it does today I
| imagine...
| lawlessone wrote:
| Are they that unpopular? Seem like a staple of an English
| Breakfast.
| Theodores wrote:
| Vitamin D supplementation in the UK - now there is a
| fascinating topic.
|
| With the industrial revolution there was a problem of kids
| in cities getting rickets. This was due to a lack of
| vitamin C and that was due to a lack of daylight due to the
| smog.
|
| The solution was to take the kids out of the city so they
| could spend time in the countryside.
|
| However, along with the industrial revolution came steam
| trains, and, with steam trains, it became a lot easier to
| get fresh food from the farm to the city table.
|
| Milk became an early commodity for this railway trade, in
| the days before refrigeration. Bottling had to be invented
| too, along with pasteurisation to get the modern milk
| product. They fortified it with vitamin D and, in time,
| made it mandatory in schools for kids to have dinky bottles
| of milk for their morning break. All kids hated the stuff
| but it was 'good for them' and good for keeping farmers
| gainfully employed.
|
| Then the clean air acts came along, with the first street
| to ban fires in fireplaces being opposite the smoke free
| coal factory, the factory being anything but smoke free.
| Deindustrialisation happened too, so there were no cities
| with smokestack industries at their heart.
|
| With clean air there was no longer any need to fortify the
| milk with vitamin D, so that stopped. From now on, kids
| would get their vitamin D doing things such as playing in
| the school playground.
|
| But then we became seriously car dependent and the age of
| the free-range child was over. With 'stranger danger' and
| screens (initially just TV) taking over, we entered a new
| era of people not getting enough daylight again.
|
| Along the way vitamin D has been downgraded, much like
| Pluto, from being a 'vitamin' to being a hormone. A lot of
| people want to point this out and explain the science to
| you. From hearing how some talk about vitamin D, it sounds
| like the recommended supplements are all over the place.
|
| Clearly there are millions, if not billions that seem to be
| living just fine with not much sunlight in their lives and
| on no vitamin D supplements. Where's the rickets? Good
| question, but then, in Antarctica, where there are months
| of darkness to endure, they are on something like 20,000
| units a day, and they probably know what they are doing.
|
| Maybe following their example for this winter could be my
| next 'nutrition experiment'. Sometimes, when there is so
| much conflicting information, it is best to do an n=1
| experiment with one's own body.
| thewebguyd wrote:
| > Maybe following their example for this winter could be
| my next 'nutrition experiment'
|
| Anecdotal and a sample size of 1, but I tried
| supplementing Vitamin D last year in the winter months. I
| live in the PNW, which between October and March, the sun
| is too low to trigger vitamin D synthesis in the skin to
| see if it had any effect on my energy levels and mood, I
| suffer from seasonal affective disorder pretty severely.
|
| Taking 5,000 IU daily had no noticeable effect for me. A
| slight increase in energy levels but not significant
| enough that I'd be confident in attributing it to
| supplementation. I was hesitant to supplement more
| without medical advice and a blood test.
|
| That's not to say Vitamin D isn't important (it is), and
| the scientists in Antartica definitely know what they're
| doing, but it's more to say YMMV.
|
| For me, just making an effort to do more physical
| activity outdoors during the dark months had more of an
| impact
| LtdJorge wrote:
| > This was due to a lack of vitamin C and that was due to
| a lack of daylight
|
| I think you also meant Vitamin D there
| hinkley wrote:
| It's criminal that the US sent Somalian refuges to live in
| Minnesota. Those are some seriously brown people in the land
| of no vitamin D. Pretty big population in Seattle as well,
| which is worse due to cloud cover.
| sedivy94 wrote:
| Minnesota, not Wisconsin. Same latitude and a fair point.
| hinkley wrote:
| I knew it was Minnesota, not sure why I wrote WI.
| mwambua wrote:
| It's only criminal if they aren't provided with the
| education/information they need to live healthy lives
| (which is possible with the right diet/supplements).
| hinkley wrote:
| Dark skinned people do not produce enough vitamin D in
| northern latitudes because of melanin. If you're black
| and in Minnesota you probably need supplementation.
| mwambua wrote:
| I'm painfully aware of that being dark skinned myself.
| That doesn't mean that Minnesota is inhospitable though
| (or that it would be criminal to send me there). It just
| means that they'd need to know that they need vitamin D
| supplements and perhaps regular blood screens. Idk if
| that happens though.
| lisbbb wrote:
| They have all already disappeared form public and it's
| only in the 40s right now. By winter you would swear no
| Somalis live in MN.
| anvuong wrote:
| I'm an Asian who was born and raised in a tropical weather
| region of my country. I'm now living in the PNW region of
| the US and it's always miserable from November-April.
| Vitamin D helps but it's not the same.
| lisbbb wrote:
| It was never about doing right for people, it was about
| making unbelievable gobs of money using them as pawns.
| hinkley wrote:
| I mean I guess they could have dumped them in West
| Virginia or Kentucky and that would have been much much
| worse.
| thewebguyd wrote:
| > which is worse due to cloud cover.
|
| Not just cloud cover. Most areas in the PNW, the sun is so
| low in the sky between October and March that you can't
| synthesize vitamin D through the skin at all during those
| months, even on a bright sunny day.
|
| Even during the summer up here, you really only get a
| window of roughly 10am to 3pm where enough UV-B rays can
| penetrate the atmosphere, in July. It's estimated that >80%
| of the PNW population are deficient (compared with 40%
| nationwide in the US).
| loverofhumanz wrote:
| Man suffered outdoors very much, for a million years.
|
| Man want both good of indoors and good of out outdoors.
| barbazoo wrote:
| Man agree
| supportengineer wrote:
| Few words good
| IAmBroom wrote:
| fewer gooder
| SketchySeaBeast wrote:
| Indoors best invention since fire.
| hinkley wrote:
| Chimney next best invention.
| SketchySeaBeast wrote:
| Man love synergy.
| formerly_proven wrote:
| Fire indoors but smoke outdoors.
| hinkley wrote:
| <grunt>
| SAI_Peregrinus wrote:
| Doors are such an important invention that multiple
| unrelated animals have evolved modified body parts to serve
| as doors to burrows1. Being able to store food is
| critically important for surviving low-food periods like
| winter without migrating. "Indoors" lets you store food
| without insects or other animals getting to it & stealing
| it. Fire allows for hardening clay, which lets you make a
| special tiny "indoors" called a "pot" for storing food.
| Also bricks so "indoors" can be made anywhere. With a roof
| the rain stays out & you can stay dry & warm, and not
| freeze at night. A significant portion of why fire is so
| important is it enables creating various sorts of
| "indoors".
|
| 1https://en.wikipedia.org/wiki/Phragmosis
| thaumasiotes wrote:
| > "Indoors" lets you store food without insects or other
| animals getting to it & stealing it.
|
| This isn't true of human doors; insects are very small.
|
| We've had the technology to keep things in wax-sealed
| clay jars for quite a while, but I'm not aware that this
| was done with grain, where preventing spoilage would have
| been most valuable. Granaries are open to the air. (And
| devote quite a lot of effort to slowing the spoilage of
| the grain.)
|
| If you wanted food that wouldn't rot, instead of keeping
| it in an airtight environment, you dried it.
| IAmBroom wrote:
| Dried food requires indoor storage.
| bluGill wrote:
| Every different food idem needs to be stored differently.
| There sometimes more than one option that will work, but
| you cannot treat everything the same.
| IAmBroom wrote:
| Maybe better.
|
| If I have to survive the night, overhead protection and
| thermal insulation is more important than a fire. Source:
| I've tried using both without the other.
| SketchySeaBeast wrote:
| There's definitely a reason we use tents while camping
| and don't just huddle around the fire.
| al_borland wrote:
| While I'd love to just go for a walk outside, the allergen
| exposure of the outdoors is too high most of the time. This
| elements any mental health benefits a walk in a forest might
| otherwise give.
| yadaeno wrote:
| Allergy shots work very well.
| IAmBroom wrote:
| Privileged comment. Walks in a controlled greenhouse
| without allergenic pollinators also work, but the poor
| can't easily access either in the US.
| pavel_lishin wrote:
| > _Privileged comment._
|
| Shall we stop discussing any possible solution which
| might be out of reach for someone?
| switchbak wrote:
| Privileged commenter. Not everyone has access to a cell
| phone or the internet, so they can't respond to your
| statement. Not to mention some people have bad dyslexia
| or eyesight issues. We could play this game forever, and
| we'd all be dumber for it.
|
| Walking in a forest is something that much of humanity
| can do, and it's not a particular privilege (in the
| pejorative modern sense) - even if there are a small
| number of people that have issues that would prevent
| this.
| al_borland wrote:
| I'm currently getting allergy shots. This is my 3rd
| attempt. Throughout my life I've gotten shots for about 12
| years now. The last guy said they were better than I was
| kid and basically a cure now. 6 years later, and on the
| strongest dosage they'd give, getting 3 shots with each
| appointment... and I was never able to spend time outside
| without worry of what would follow.
|
| There has been minor improvement in controlled testing, but
| no noticeable benefit when actually trying to live life. I
| go outside near nature once each year as a test to see if
| there was any progress. I can't tolerate much more than
| that.
|
| Shots work well for some. They worked decently well when I
| was a kid, but these days, not so much. I still hope the
| current ones will work, as I don't have other options, but
| I'm beginning to lose hope.
| keybored wrote:
| How do I bring outdoors to the wage slave office? And how do I
| bring light to the pre-work and afterwork when there is _no
| sun_ at those times?
|
| The practical man uses technology to offset the prison built
| for him. The hapless enabler farms "pithy" HN points in his
| LED-lit room.
| canadiantim wrote:
| I wonder why we didn't recommend vitamin D during Covid?
| dlcarrier wrote:
| One of the best treatments is interferon. It's something you
| will also produce yourself, with therapeutic effect, if
| exposited to sunlight or the infrared light used in red light
| therapy. Here's a video about it, from a continuing education
| provider: https://www.youtube.com/watch?v=oRkxH56LqCo
|
| Vitamin D therapy doesn't have such an effect.
| Supermancho wrote:
| There were a few soft recommendations. Specifically I remember
| an ER doctor in 2019 saying vitamin D seemed to be a
| differentiator in the sample of cases he was seeing in the ER
| (everyone was starting to panic) and the CDC walking it back as
| unsubstantiated. I mentioned it at work, then 10 days later my
| boss's boss asked me where I had heard it, because he had heard
| the same thing.
|
| There have been a number of people on HN who have attributed
| any measurable COVID benefit of Vitamin D, to a confounding
| variable, as recently as 3 months ago -
| https://news.ycombinator.com/item?id=44705486 The Big Vitamin D
| Mistake
| stronglikedan wrote:
| Because the right people couldn't make money off of it - same
| reason that a lot of beneficial treatments were not recommended
| or flat out defamed.
| mda wrote:
| Unfortunately Vitamin D deficiency tests (probably it is not
| covered by your insurance), high dose supplements are currently
| pushed so much by Doctors I started to think this is almost a
| scam. Most of the research about the subject are very noisy and
| conflicting.
| mwigdahl wrote:
| If it's a scam, who's profiting? The pills are dirt cheap,
| generic, and over the counter.
| dlcarrier wrote:
| Dr. Michael Holick: https://www.nbcnews.com/health/health-
| news/selling-america-v...
| mwigdahl wrote:
| Interesting article, thanks!
| mda wrote:
| Tests are very expensive
| MandieD wrote:
| How much are they where you are? They're 20-30 EUR on their
| own in Germany (doctor's office, pharmacies)
| LocalPCGuy wrote:
| If there is any reason for the test, it would be diagnostic and
| not preventative, and that is generally covered. Just checking
| cause you want to know your levels generally wouldn't be, but
| there are any number of symptoms that could be related to that.
|
| As for it being a "scam" - there are enough valid studies that
| show what this one did, that folks who are deficient that are
| able to raise their levels tend to be slightly healthier.
|
| There isn't necessarily evidence for supplementation beyond
| "normal" range, and I do agree that no one should just take
| high-dose vitamin D supplements without data (tests) that it is
| necessary.
| biscuits1 wrote:
| "Exercise" not found in the shared text.
|
| I'm sure people who supplement or have good D levels also take
| care of themselves, generally - because they know D is one of the
| supplements that make a difference both somatic and
| psychological.
|
| And thus do better with flu/cold.
| allisdust wrote:
| It is a double blind study. what else do you want for
| confirmation ?
| ktktkgkhkke wrote:
| Just turn on an uv light for a few hours. Problem solved.
| Mistletoe wrote:
| https://www.economist.com/science-and-technology/2025/09/17/...
| xwowsersx wrote:
| Supplementing with vitamin D is honestly one of the easiest
| things you can do... it's cheap, available everywhere, and makes
| a real difference. Just make sure you're also taking magnesium
| citrate (or another good form of magnesium) with it, since your
| body needs magnesium to properly use vit D
| johnisgood wrote:
| And K2.
|
| As for magnesium, I would go with magnesium glycinate or
| magnesium threonate.
| xwowsersx wrote:
| Absolutely. And you're totally right about magnesium
| glycinate. That's what I take. I don't know why I said
| citrate.
| Etheryte wrote:
| An even better option is to go to your GP and have them run
| your bloodwork. It's cheap, depending on where you're from it
| might even be free, and you don't have to guess or randomly
| pick supplements you read about online. Most people on HN will
| live to a very high age, there's no reason to take random
| gambles on what you do to your body.
| xwowsersx wrote:
| For sure, you're essentially flying blind without bloodwork.
| I get a full panel at least 3x/year.
| Aldipower wrote:
| 3-4 years ago this submission would be flagged in seconds just
| because of the word Vitamin D.
| CGMthrowaway wrote:
| Reminder that the Recommended Daily Allowance of Vitamin D found
| on all the labels (800 IU) is mistakenly too low, by a factor of
| 10x, due to a maths error (should be 8000 IU). It has not been
| corrected yet. Source:
| https://pmc.ncbi.nlm.nih.gov/articles/PMC5541280/
| lostdog wrote:
| I take 10k IU of vitamin D if I feel a cold coming on. I used to
| get extremely bad colds very frequently, and every time I get
| frustrated and read whatever research might be helpful. A year
| ago I came across some info about LL-37, and found that vitamin D
| might help, and that's when I started taking it.
| https://pmc.ncbi.nlm.nih.gov/articles/PMC9134243/
|
| The big dose of D seems to help. I'm certain I'm deficient, since
| I already take 2-4k daily, which noticeably helpsy winter blues.
| It's the first time I can "arrest" a cold, and even if I get sick
| the symptoms aren't nearly as bad.
|
| My full protocol for if I start feeling a cold is this:
|
| 1. 10k vitamin D 2. Stay extremely warm when I sleep.
| Uncomfortably warm. 3. Butyrate (probably a placebo) 4. Curcumin
| (almost certainly a placebo).
| turtlebro wrote:
| Take like 2g of Vitamin C. It's a lot stronger. Vitamin D is
| good too, but if anything you want to take C.
| elil17 wrote:
| I personally found that taking vitamin D regularly dramatically
| reduced how many colds I got (10 in 2024 vs. 1 in 2025).
|
| I take 2,000 IU per day, typically without a meal.
| Liquix wrote:
| > typically without a meal
|
| any reason why? it's fat soluble and absorbs much better if
| taken with a meal.
| Etheryte wrote:
| Unfortunately this is a common error people make, many
| vitamins and other supplements are absorbed better when taken
| with food, even if that seems counterintuitive at first.
| mrmuagi wrote:
| Another thing I am curious about is time of day too -- I
| was told vitamin D/Multivitamins were better taken in the
| morning with food.
| cj wrote:
| It really depends. Other things like iron is best taken
| fasted (and paired with Vitamin C). Coffee also blocks iron
| absorption, so many people supplement at nighttime. Also
| things like Zinc and Copper both compete with each other
| for absorption, so best to avoid taking them at the same
| time.
|
| If you're optimizing your supplement stack, really gotta
| research each one individually (and how each impact the
| absorption of the others)
| elil17 wrote:
| Because I always forget lol. My point is that I still had a
| good effect even though I'm doing an extremely sub-optimal
| job of taking it/probably getting a dose-equivalence of way
| less than 2k IU/day.
| mberning wrote:
| In the US it is very easy to test your vitamin D levels. I
| recently had mine done and was just below normal range. Started
| supplementing and will test again in 6 months.
| kraig911 wrote:
| I wonder if adding zinc on top of this would do.
| IAmBroom wrote:
| Would do...? Zinc taken the first day of symptoms _may_ reduce
| the duration of a cold by a day on average. It 's probably
| useful, but not certain.
|
| Be sure to take zinc with meals, or your stomach may hate you.
| pewpewp wrote:
| Interesting how your government did not mention Vitamin D during
| the COVID scare.
| boilerupnc wrote:
| A few other interesting links with Vitamin D absorption.
| Surprised nobody has brought up gut dysbiosis and the role
| microbiome plays in Vitamin absorption. I'm finding it
| increasingly difficult to discern whether the things we consume
| are for the direct benefit of our cells and metabolic needs or
| via a more indirect path if the things we consume directly affect
| the microbiome within us which then translates into either
| nourishment or inflammation within us. Since microbiomes can
| change rapidly in composition, this feels like a game of
| nurturing over the long-haul with some minor blips along the way.
|
| [1] "connection between vitamin D and the immune system through
| gut bacteria and may have applications for improving cancer
| therapies"
|
| [2] "How the Gut Microbiome Affects Vitamin D Absorption"
|
| [3] "vitamin D may affect the host-microbiota relationship."
|
| [1]: https://www.science.org/doi/10.1126/science.adh7954
|
| [2]: https://www.gutnow.com/medical-treatments/how-your-gut-
| micro...
|
| [3]: https://journals.asm.org/doi/10.1128/spectrum.00083-24
| gwerbret wrote:
| Heh...this is a shady study if I ever saw one.
|
| -- Exactly 400 study participants recruited.
|
| -- Exactly 193 of 200 participants completing the study in each
| group (which, for a study administered in a community setting, is
| an essentially impossibly-high completion rate).
|
| -- No author disclosures -- in fact, no information about the
| authors whatsoever, other than their names.
|
| -- No information on exposures, lifestyles, or other factors
| which invariably influence infection rates.
|
| -- Inappropriate statistical methods, which focus very heavily on
| p values.
|
| -- Only 3 authors, which for a randomized controlled trial
| involving hundreds of people in different settings with regular
| follow-up, seems rather unlikely.
| roflmaostc wrote:
| In the PDF they are all titled as
|
| "Assistant Professor, Department of General Medicine, Arundathi
| Institute of Medical Sciences, Dundigal, Medchal Malkajgiri,
| Telangana, India"
|
| The 2nd author is listed here: https://aims.ac.in/general-
| medicine/ I did not find any trace for the other two authors
| (do they exist?).
|
| Also, look at the timings: Received: 16-09-2025 Accepted:
| 29-09-2025 Available online: 14-10-2025
|
| That's relatively fast but also the paper is not super in-
| depth.
|
| And in general it seems like that the "International Journal of
| Medical and Pharmaceutical Research" is not quite well known.
| See the Editors, not even pictures there:
| https://ijmpr.in/editorial-board/
| roflmaostc wrote:
| The first author is probably him: Dr. G Naresh (Asst. Prof.)
|
| https://aims.ac.in/general-medicine/
| roncesvalles wrote:
| My bullshit meter redlined as well.
|
| > Incidence of ARIs was documented through monthly follow-up
| visits and self-reported symptom diaries validated by physician
| assessment.
|
| This is basically impossible to accomplish for 386 participants
| who aren't in some form of captivity (e.g. incarcerated,
| institutionalized, in the military, or a boarding school).
| Nobody cares enough to maintain a "self-reported symptoms
| diary" and make monthly visits for some study. If they actually
| ran the study as designed, they would've have zero usable
| participants even starting from 400.
|
| Saying nothing of the ethics of giving half the Vitamin D
| deficient patients presenting at your clinic with a placebo.
| givemeethekeys wrote:
| > (e.g. incarcerated, institutionalized, in the military, or
| a boarding school).
|
| That's a pretty big list. Add Retirement communities and your
| pool increases even more. Add to that the fact that this is
| India where the population is at least 5x bigger and much
| more concentrated..
| bluGill wrote:
| Most retirement communities don't have that much
| supervision.
|
| Regardless, you can get a lot of data, but of it is from
| people who have other significant differences in lifestyle
| from the average person and so it is questionable how it
| applies. Military gets more physical fitness (we already
| know most of us need more). Boarding school implies young -
| children or just older, and so while not useful there are
| differences related to that to control for (military as
| well, unless you can get officers who are older thus
| allowing controlling for age).
| JumpCrisscross wrote:
| > _Most retirement communities don 't have that much
| supervision_
|
| Retirement communities in India are relatively new. Most
| older folks get taken care of at home by domestic staff,
| which, given India's demographics, are incredibly cheap
| and thus plentiful.
| bluGill wrote:
| I forgot this was India, my mistake. Though that means
| there are essentially no retirement communities to work
| with there.
| givemeethekeys wrote:
| There are retirement communities in India and end-of-life
| care centers as well. Societies change, and thanks to the
| internet, societies change faster than ever.
| hinkley wrote:
| I was pretty sure we already knew vitamin D deficits dampen the
| immune system.
| croes wrote:
| So a vitamin deficit is bad for your health.
|
| Shocker.
| alphazard wrote:
| A lot of people are critiquing the statistical methods and
| quality of the study, which is fine. But it's worth pointing out
| that you--the individual--should not be concerned with someone
| else's p-value. You should be concerned with maximizing your own
| utility. A safe, possibly effective, and cheap intervention is
| probably worth trying. If it was more expensive or less safe, it
| would require more evidence to try.
| saretup wrote:
| There can be hundreds of safe, _possibly_ effective, and cheap
| interventions. Can't try them all. Higher quality of evidence
| helps narrow it down.
| oldestofsports wrote:
| Breaking news! Water proven to clench thirst among those who are
| thirsty!
| lr4444lr wrote:
| Do we really know what "optimal" vitamin D levels are? I've heard
| a wide range of answers on this, and it's not even clear to me
| that we know whether there is natural human variability in the
| amount needed.
| dynm wrote:
| This paper states:
|
| > The study protocol was approved by the Institutional Ethics
| Committee and registered with the Clinical Trials Registry of
| India
|
| As far as I can tell, that registry is here:
| https://www.ctri.nic.in/Clinicaltrials/pubview.php
|
| Doing a keyword search for the first author's last name reveals
| zero hits. (It's possible I'm missing--that search does not
| inspire confidence.)
| patel011393 wrote:
| Take it from an academic like me that peer review in just over a
| month is rare and a sign of low-quality editorial work at the
| journal (the exceptions would be the most open, progressive
| journals like PCI and similar).
|
| The formatting/style and peer review history alone are enough for
| me to doubt this. Of course, the other users' points about study
| design and lack of transparency make it even harder to trust the
| claims.
| lisbbb wrote:
| What about the article that that talks about Vitamin D being the
| same chemical as rat poison and that the positive effects it has
| on our bodies may be due to the fact that we are low-level
| poisoning ourselves with it?
|
| "Vitamin D3, also known as cholecalciferol, is used as a
| rodenticide because it is highly toxic to rodents when ingested
| in sufficient quantities. It functions by causing a life-
| threatening elevation in blood calcium and phosphorus levels,
| leading to severe acute kidney failure"
|
| "Despite its use in rodenticides, vitamin D3 is safe for humans
| and pets when consumed in normal dietary or supplement doses.
| However, extremely high doses of vitamin D3 can be toxic to
| humans as well, potentially leading to hypercalcemia, kidney
| stones, and renal failure. The difference in susceptibility
| between rodents and humans is significant; rodents are much more
| sensitive to the effects of cholecalciferol, which is why it is
| effective as a rodenticide."
|
| The theory is that we are just poisoning ourselves by taking it
| and that our bodies react to being poisoned with the positive
| effects that are well documented and observed.
| astrostl wrote:
| I haven't seen convincing evidence that vitamin D supplementation
| is materially useful for anything but rickets. I get the
| impression that naturally high serum levels are an effect rather
| than a cause of other positive things, and that supplementation
| mostly increases serum levels without effecting positive things.
| It doesn't seem harmful either, so can't hurt might help?
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