[HN Gopher] Vit D supplementation to prevent acute resp infectio...
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       Vit D supplementation to prevent acute resp infections: review and
       meta-analysis
        
       Author : bookofjoe
       Score  : 55 points
       Date   : 2025-04-09 17:26 UTC (5 hours ago)
        
 (HTM) web link (www.thelancet.com)
 (TXT) w3m dump (www.thelancet.com)
        
       | gnabgib wrote:
       | Related
       | 
       |  _High-dose Vitamin D reduces disease activity in early multiple
       | sclerosis onset_ (91 points, 15 days ago, 52 comments)
       | https://news.ycombinator.com/item?id=43469661
       | 
       |  _Over 80% of Covid-19 patients in a hospital study have Vitamin
       | D deficiency_ (654 points, 4 years ago, 363 comments)
       | https://news.ycombinator.com/item?id=24912172
       | 
       |  _Adequate Vitamin D Levels Cuts Risk of Dying from Covid-19 in
       | Half, Study Finds_ (372 points, 5 years ago, 211 comments)
       | https://news.ycombinator.com/item?id=24607645
        
       | rwbt wrote:
       | Just curious, other than taking Vitamin D pills - what are some
       | natural diets that are rich in Vitamin D?
        
         | daveguy wrote:
         | There are a lot of every day foods with a good supply of
         | vitamin D.
         | 
         | https://www.dietaryguidelines.gov/resources/2020-2025-dietar...
         | 
         | I recommend saving a copy of .gov website sources in case the
         | regime decides it is unacceptable speech.
        
           | gnabgib wrote:
           | Sources: Fish (generally fatty: trout, salmon, tuna, herring,
           | sardines, tilapia, flounder), Mushrooms (some, large variety
           | in quantity).
           | 
           | Note the article is "food sources" so it includes fortified
           | (dairy, juice) which _do not_ contain vitamin D naturally.
        
             | daveguy wrote:
             | Uh. Okay buddy, thanks for that.
             | 
             | P.S. most milk sold in the US is Vitamin D fortified.
        
             | adrian_b wrote:
             | The substance in mushrooms (ergocalciferol) has a structure
             | similar to the true vitamin D (cholecalciferol a.k.a.
             | vitamin D3).
             | 
             | Nevertheless, it seems that it is not able to substitute
             | vitamin D in all its functions. Therefore it is not
             | advisable to count on it as a source of vitamin D.
             | 
             | There has been a company that has claimed that they have
             | discovered a species of lichen that contains true vitamin
             | D. Nevertheless, their advertising has seemed highly
             | suspicious and it looked more like a scheme to separate
             | naive vegans from their money.
             | 
             | Even if it were true, exploiting wild lichen would be much
             | more unethical than eating the normal vitamin D3
             | supplements made from sheep wool. The reason is that wild
             | lichens grow very slowly and exploiting a species for a
             | food supplement would cause a very high risk of extinction
             | for that species.
             | 
             | In any vertebrate animal, the liver is the part with the
             | greatest content of vitamin D.
        
         | meroes wrote:
         | According to my doctor, raising vit D through diet is not
         | reasonable. It's sunlight or pills/shots if sunlight won't do
         | it (genetics or climate).
         | 
         | In peak summer with being outdoors 2+ hours every day my Vit D
         | was 30 (<30 is inadequate) and drank fortified almond milk
         | daily. In winter it drops to 20 with similar outdoor time. Been
         | on a 50,000 pill once a week since.
         | 
         | Maybe someone will share a well informed diet that contradicts
         | my doctor.
         | 
         | I get the sense that you have to eat a lot of fish, which
         | introduces heavy metal concerns because of modern fishing,
         | which is why my doctor went the route he did. And how do you
         | know the one type of mushroom actually gets the right light to
         | have natural Vit D---raw ingredients like mushrooms don't
         | usually have nutrition labels.
        
           | Aurornis wrote:
           | > Been on a 50,000 pill once a week since.
           | 
           | FYI, spiking Vitamin D levels in the blood weekly might not
           | be the best idea, though it's not exactly proven. There's a
           | theory that spiking Vitamin D like that can promote blood
           | vessel calcification. There's some more theory that Vitamin K
           | administered at the same time might help.
           | 
           | It could be safer to do 5,000 IU seven days a week than
           | spikes of 50K once a week.
           | 
           | Watch out, though. I was on a similar daily dose and ended up
           | with Vitamin D levels touching the upper limit. Too much
           | Vitamin D is not good for you.
           | 
           | > and drank fortified almond milk daily.
           | 
           | Can't say without seeing the labels, but I wouldn't expect a
           | cup of almond milk to have more than 10-20% of your daily
           | value.
        
             | johnisgood wrote:
             | IIRC supplementing K with D also helps D to be absorbed
             | and/or utilized better.
        
           | canucker2016 wrote:
           | Are you getting enough Magnesium (and also Vitamin B6)?
           | Magnesium is a required cofactor of Vitamin D in many bodily
           | processes.
           | 
           | see https://www.qeios.com/read/479KRZ
        
         | adrian_b wrote:
         | Cod liver oil is probably the best choice, as it also includes
         | DHA, EPA and vitamin A, providing most things that would not be
         | provided by vegetable oil (the only essential fatty substance
         | that is neither in vegetable oil nor in cod liver oil is
         | vitamin K2).
         | 
         | Well made cod liver oil is tasty and you can add it to food
         | together with whatever else kind of oil you prefer (after food
         | is cooked, not before, as it is heat sensitive). No more than
         | 10 mL/day is necessary.
         | 
         | At least at the analysis reports that I have seen in the EU,
         | fish oil has never been found with high content of mercury,
         | even if the fish from which it has been extracted are likely to
         | have been contaminated with mercury. Moreover, cod liver oil is
         | sold in the EU as recommended for children and pregnant women.
         | I doubt that any company would have the guts to sell such
         | products here without taking care to make frequent chemical
         | analyses to ensure that the product is never contaminated.
         | 
         | Chicken liver is also rich in vitamin D, but it is not
         | advisable to eat great quantities, because it may contain too
         | much vitamin A (which is toxic in excessive amounts). The
         | amount of vitamin A in chicken liver or turkey liver is pretty
         | much unpredictable, because it may vary by more than an order
         | of magnitude between various producers, depending on how they
         | feed the birds.
         | 
         | Most vitamin D3 pills contain vitamin D3 that is produced from
         | sheep wool (i.e. from lanolin).
        
         | moltar wrote:
         | Not possible with diet alone.
        
       | moltar wrote:
       | Recommend dminder app for an illuminated way to count D intake
       | from both sun and supps.
        
       | mrandish wrote:
       | Having looked pretty deeply into Vit D studies a while back, my
       | takeaway was (in broad strokes):
       | 
       | * Adding more Vit D doesn't appear to meaningfully _prevent_
       | upper respiratory infections.
       | 
       | * However, being _deficient_ in Vit D appears to be correlated
       | with a meaningful number of D deficient people who do happen to
       | get an upper respiratory infection having a more serious impact.
       | Basically, a higher percentage of deficient people (but certainly
       | far from all) appear to have worse symptoms for longer and have
       | more trouble fighting the infection off. Whether that just means
       | an extra day of feeling under the weather or that you join the
       | very small percentage of those hospitalized for upper respiratory
       | infection depends on the other factors you already know (age,
       | overall health, etc) _much_ more than on Vit D deficiency. But
       | Vit D deficiency is very probably in the top 5 somewhere behind
       | the two statistical Godzillas at the top, age and overall health
       | (which are overwhelmingly correlated).
       | 
       | This is only worth talking about because a fairly significant
       | number of people are Vit D deficient at least some of the time
       | (probably more than 20% but less than half). Who and how much
       | depends on where they live, lifestyle, age, diet, time of year
       | and there is also a genetic propensity for deficiency that's
       | primarily based on race.
       | 
       | Bottom line: If you're Vit D deficient then it may be a good idea
       | to supplement a little Vit D which is cheap, easy and extremely
       | low risk (Note: nothing is ever zero risk across a large enough
       | population but supplementing a small amount of Vit D is about as
       | safe as these things ever get). It may be especially worth
       | considering if you're in a statistically higher risk group,
       | location and/or season. So, if you're at elevated risk and can't
       | be younger or healthier, at least don't be Vit D deficient too.
       | Once you're not deficient, taking even more Vit D won't help more
       | (and can be harmful). Mega-dosing can definitely be harmful, so
       | please don't. Starting oral supplements once you have symptoms is
       | also too late to matter.
       | 
       | In terms of confidence levels, my sense was there's pretty
       | clearly a meaningful correlation here but causation and relative
       | effect are fuzzy. The correlation mostly comes from looking
       | retrospectively at the Vit D levels of those who have infections
       | serious enough to get hospitalized. However, the Vit D
       | correlation is far less than age or overall health (which are
       | overwhelmingly large). The challenge is looking at it the other
       | way, from the front end, where it gets pretty fuzzy trying to
       | tease out high confidence causal data, narrow other factor's
       | contributions or derive a degree of impact specific to Vit D.
       | There are a lot of potentially confounding factors and Vit D is
       | not usually checked in many blood work panels unless there's a
       | reason to. Worse, long-term diary studies of diet are
       | _notoriously_ inexact. So much so that as an armchair amateur
       | scientist just trying to objectively assess data, I have to
       | attach error bars to longitudinal diary diet studies so large
       | they usually swamp any signal. For example, the question:  "Does
       | being Vit D deficient meaningfully increase _susceptibility_ to
       | infection? " I don't think there's sufficiently clear data to
       | make any judgement.
        
         | timrichard wrote:
         | > you'll just pee out the extra Vit D.
         | 
         | It's fat soluble, rather than water soluble
        
           | adrian_b wrote:
           | True.
           | 
           | I have not checked this, but I assume that most excess
           | vitamin D, which is stored in the liver, is excreted by the
           | liver together with cholesterol and other cholesterol
           | derivatives, in the biliary secretion, reaching thus the
           | intestine, and not by the kidneys in urine.
        
           | mrandish wrote:
           | Thanks! I removed that line.
        
         | slibhb wrote:
         | > Bottom line: If you're Vit D deficient then it may be a good
         | idea to supplement a little Vit D which is cheap, easy and
         | extremely low risk (Note: nothing is ever zero risk across a
         | large enough population but supplementing a small amount of Vit
         | D is about as safe as these things ever get).
         | 
         | Too much vitamin D can cause pretty serious symptoms, including
         | neurological symptoms. This condition has been getting more
         | common since so many people are supplementing.
        
           | p0w3n3d wrote:
           | I read somewhere that additionally supplied vitamin K
           | decreases these side effects. However I'd like to see a
           | scientific paper instead of an article
           | 
           | https://www.health.com/vitamin-d-and-k-8427006
        
           | kstrauser wrote:
           | Very true. That said, I've been taking 5000IU daily for the
           | last couple years after a blood test showed my levels were a
           | bit low. As of last week, my 25-Hydroxy D level is 76, near
           | the middle of the 30-100 normal range.
           | 
           | Everyone's different: what's right for me isn't right for
           | you. I just mean that to demonstrate that it's possible for
           | some healthy adults to take a pretty significant amount every
           | single day and have perfectly reasonable blood levels.
        
           | Aurornis wrote:
           | Vitamin D has a very long half-life in the body once stored.
           | On the order of a month or two.
           | 
           | This leads a lot of people into slowly overdosing over
           | several years. They start with low levels, get up to mid-
           | range on their next blood test, and think they're on the
           | right track. Continuing the same dose for years can easily
           | put you over the top if you're not careful.
        
         | AStonesThrow wrote:
         | If we're deficient then it may well mean that our bodies aren't
         | being accorded the _usual natural_ opportunities to manufacture
         | it!
         | 
         | Therefore a deficiency here is an indicator of sedentary,
         | indoor, face-in-a-screen lifestyles that risk all sorts of poor
         | health conditions.
         | 
         | The solution to D deficiency is to manufacture it by touching
         | grass, enjoying sunlight (unprotected!!!) and exercising--not
         | in a gym--but in that extremely large room, lit by a bright,
         | warm lamp that's 93 million miles away.
        
           | SoftTalker wrote:
           | Just taper into the sunlight exposure so you don't get burnt.
           | Skin cancer is not really a price you want to pay for
           | adequate Vitamin D levels.
        
             | AStonesThrow wrote:
             | Skin cancer is not something I anticipate, since I
             | scrupulously avoid slathering carcinogens onto it. I
             | protect with clothing, umbrellas, and old-fashioned hanging
             | out in the shade [my skin tone is porcelain, minimal
             | freckling, 100% Celtic edition]. 26 years in Phoenix metro
             | with literally no burns and no cancer: homelessness and
             | public transit benches notwithstanding.
        
           | jerf wrote:
           | We don't need to hypothesize about our bodies not getting the
           | natural opportunities to manufacture it. We know we don't.
           | Plenty of people live in places where the sunlight is
           | insufficient for significant portions of the year to generate
           | any vitamin D. Many others live in places where they may
           | nominally be getting enough ultraviolet to make enough
           | vitamin D, but have too much melanin in their skin for the
           | ultraviolet conditions where they live.
           | 
           | This isn't all about "oooh sooo much indoors too much screen
           | time stop sitting so much lol lol lol". You can go outside
           | all day in the middle of winter at the 45 degree latitude,
           | where a lot of people live, and you will generate zero
           | vitamin D, no matter what you do, because it isn't the
           | visible spectrum you need. You need something that isn't in
           | the winter sunlight at all. AIUI, it's technically not the
           | same part of the UV spectrum that causes sun burns, but
           | you're at least on the right track if you think of it as if
           | you can't burn (modulo melanin), you can't generate vitamin D
           | at all.
        
         | niemandhier wrote:
         | To much words for truth:
         | 
         | More does not help by to little will harm.
         | 
         | I live where the sun does not shine, so I take some.
        
       | brokegrammer wrote:
       | The title is wrong. The study concluded that Vitamin D
       | supplementation doesn't help prevent acute respiratory
       | infections.
        
         | noselasd wrote:
         | The title doesn't contain any conclusion.
        
           | brokegrammer wrote:
           | Right, my bad. Misleading would be the correct word.
        
             | bookofjoe wrote:
             | Full title as published in Lancet:
             | 
             | >Vitamin D supplementation to prevent acute respiratory
             | infections: systematic review and meta-analysis of
             | stratified aggregate data
             | 
             | What with HN's 80 character limit something had to go!
             | 
             | I apologize for making it "misleading" but what would you
             | have done?
        
               | tweetle_beetle wrote:
               | No need to apologise. It's not misleading at all.
        
               | zerr wrote:
               | It's lacking. A good title should save a click for those
               | who are not interested in details but just the
               | conclusion.
        
               | bookofjoe wrote:
               | I ask again: what do you believe the title should be?
        
       | seizethecheese wrote:
       | > For the primary comparison of any vitamin D versus placebo, the
       | intervention did not statistically significantly affect overall
       | ARI risk (OR 0*94 [95% CI 0*88-1*00], p=0*057; 40 studies; 61 589
       | participants; I2=26*4%).
       | 
       | Okay, so the 95% confidence interval is reduction from 0% to 12%,
       | but since this barely is on the other side of p=0.05 the
       | conclusion is fully that the claim is not supported.
        
         | Aurornis wrote:
         | The more interesting finding is that people with low baseline
         | Vitamin D levels (<25 nmol/L) did not show any improvement.
         | Odds ratio of 0.98 (0.80-1.20).
         | 
         | A lot of previous Vitamin D research was dismissed with the
         | claim that Vitamin D would be more effective if you only looked
         | at people with low baseline Vitamin D status. This paper does
         | not show that to be true.
        
       | johnisgood wrote:
       | For what it's worth, it is good to know:
       | 
       | - Low Vitamin D Status despite Abundant Sun Exposure
       | (https://academic.oup.com/jcem/article/92/6/2130/2597445)
       | 
       | - Vitamin D deficiency can still occur despite supplementation
       | (https://emedicine.medscape.com/article/128762-overview?form=...,
       | https://www.ccjm.org/content/89/3/154,
       | https://www.health.harvard.edu/healthbeat/9-things-that-can-...)
       | 
       | Thus, you can be deficient despite sun exposure and/or
       | supplementation.
       | 
       | You should probably get tests done to be sure.
       | 
       | I have MS, I take daily 10k IU. I should probably get some tests
       | done myself.
        
       | normalaccess wrote:
       | For anyone who is familiar with the Security Now podcast there is
       | an excellent write-up from Steve Gibson on the topic for nerds as
       | we all work in man made caves and don't get sun. _Highly
       | recommended._
       | 
       | I would also recommend Dr. John Campbell's videos on the topic as
       | he is quite thorough when reviewing the medical research.
       | 
       | One interesting point John makes is that if you are already sick
       | Vit D is to slow as it needs to metabolize and calcifediol
       | (25-hydroxyvitamin D3, the active form) is what patents need
       | after infection.
       | 
       | Links:
       | 
       | https://www.grc.com/health/vitamin-d.htm
       | 
       | https://www.youtube.com/@Campbellteaching/search?query=vitam...
        
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