I suffer from allergic asthma and tend to catch colds quite frequently.
This year I started supplementing with 2000 UI of vitamin D daily and it's as if my immune system started functioning normally, in the last 10 months I only caught a really light cold that I could barely notice, whereas before this the winter season alone would bring 2 severe cold or flu episodes that would knock me down for several days.
I can't really say if it's the vitamin D, or other changes in my life, like losing some weight or walking more, or the cold exposure I've been practicing (primarily because I heard it burns calories :-)), it might be even placebo, I haven't isolated these variables well, but my wife and close ones are amazed by the transformation. E.g. 3 weeks ago everyone in my household got the flu, except for me.
So now I got everyone in my household on vitamin D, especially b/c of this coronavirus scare. During summer time we might not need it, but the sun doesn't see us during winter. And vitamins are probably no defense against the coronavirus, but a deficiency could amplify the damage (as vit D has a role in our immune system) so it's best to ensure that we aren't deficient. Also we tolerate large doses of vitamin D, so it can't hurt.
I have a really funky immune system. I have psoriasis for starters, and in 2017 I had to have neurosurgery to remove strep B from my spinal column and learn how to walk again because my immune system hadn't been able to fight it off.
I have reduced my alcohol intake, lost weight and have been taken medication that isn't an immunosuppressant (acetretin), for the psoriasis, along with the NHS giving me a free flu jab as I'm in an at-risk group despite being only in my early 40s.
I was taking vitamin D back in 2017 after it was recommended to me by one of the doctors, but slowly got out of the habit, and I'm now wondering if it can help with some of this. I have a jar of 3000 UI knocking around, so I'll start taking it today, and see how this goes - I have an outward looking signal on how well my immune system is behaving based just on my skin condition, which I've lived with for years so should be a good indicator of whether it improves or not.
If you want to know more, just ping me via the channels mentioned in my profile and I'll happily update in a month or two - let's see if I can provide a sense of it!
I had MS-like symptoms about 2 years ago: weird sensations on my skin, sudden pain spots, random ant-like crawling sensations, etc... they were getting worse but MRI came fine, Spinal Fluid testing came fine, etc...
However, my vitamin D levels were low. I started taking D3 and noticed that some symptoms got worse at first but gradually went away after a few weeks. Now, every time symptoms come back, I take vitamin D and they are gone a few days later.
I have been supplementing with varying amounts of D3 since 2010. That year a housemate had come down with a bad flu and I handed him 4000IU as an "anti-inflammatory". The next day he knocked on my door ecstatically and asked what that was. His symptoms had nearly disappeared.
And in the past decade, I can count only a few times when I was struck hard by cold or flu, and they were when I had let supplementation trail off. When I'm having it daily, then the typical inflammatory symptoms only appear near or past the peak of the infection, and otherwise it just presents as tiredness and scatterbrained thinking, which I have learned to notice and pay some attention to.
I currently believe that some theraputic benefit may continue up to 8000 IU or so, but this is purely guesswork on my part, having tried amounts higher and lower. What I am confident in saying, having reviewed the research recently, is that there is some clinically studied, but poorly understood positive correlation between vitamin D supplementation and regulation of cytokine production, which is crucial for surviving the symptoms of respiratory diseases of this type.
I've checked my 25-OHD levels before (which prompted my doctor to recommend vitamin D supplements) and 6 months after.
95% of the population need supplementation with 1700 UI to reach a serum level of 75nmol/L (considered optimal) [1]. Men can metabolize 3000-5000 UI [2]. The body adapts to higher doses by stopping solar synthesis thus we can tolerate up to 10000 UI [3].
Also vitamin D is a fat soluble vitamin and a supplement isn't necessarily absorbed well. Thus 2000 UI is generally recommended for individuals that have sub-optimal levels (this was a prescription from my doctor which is fairly standard) and it isn't considered toxic if you take up to 10000 UI.
Thankfully I don't seem to suffer from pollen allergies, my sensitivities are to cats (saliva) and to moisture and mold, so I don't have a time of year in which I'm sensitive. I do regret not being able to adopt cats :-(
When I was in my twenties I've gone through severe asthma episodes, due to exposure to such allergens and once you get inflamed it's really hard to reverse without proper treatment. So I eventually went on a treatment with corticoids and Symbicort and by avoiding the problematic allergens I've been fairly well under control ever since, haven't needed any treatment for years. Before that I was using Ventolin, which wasn't working well and gave me tachycardia episodes, thank god treatment for asthmatics got better.
But I remained fairly sensitive to colds, many colds I catch evolve into bronchitis.
> This could lead to a recommendation of 1000 IU for children <1 year on enriched formula and 1500 IU for breastfed children older than 6 months, 3000 IU for children >1 year of age, and around 8000 IU for young adults and thereafter. Actions are urgently needed to protect the global population from vitamin D deficiency.
Essentially, the recommended intake that pharmacists and labels tell you is outdated and founded in a statistical error. Adults are recommended to take >8,000IU every day and not ~1,000IU as still believed by many professionals who last updated their brainbase decades ago.
I'll counter that with a quick quote from wikipedia:
> Recommendations stemming for a single standard for optimal serum 25(OH)D concentrations ignores the differing genetically mediated determinates of serum 25(OH)D and may result in ethnic minorities in Western countries having the results of studies done with subjects not representative of ethnic diversity applied to them. Vitamin D levels vary for genetically mediated reasons as well as environmental ones.
Basically, rarely is anything simple enough for a "one size fits all" approach.
I wouldn't say you 'countered' OP with that quote, but you did add some very pertinent and helpful info. From my perspective, though, your info is syngergistic with OP's, not counter to it.
While this is a very interesting paper, I'm a little bit wary of research articles that only have a single author. Are you aware of how accepted this viewpoint is in the wider research/medical community? For example, are there any medical bodies that currently actually recommend adults to take 8000 IU of vitamin D supplement per day, if they are at risk of deficiency? Conversely, are the medical bodies that do not make such a recommendation simply slow, or are they in fact disputing the above findings?
Reminds me of a seemingly smart and reasonable doctor I once saw for an annual check. Upon hearing that I'd been taking 3,000 IU, the guy completely Lost. His. Shit. I got a lecture about not going against FDA recommendations, which is 400 IU. The "outdated brainbase" phenomenon with doctors is too real.
As a layperson it feels to me like research in the "megadose on vitamins to prevent illness" area is kind of tainted by the legacy of Linus Pauling, who was no doubt a genius in his fields and whose published literature advocated the position that vitamin C megadose would reduce cancer deaths by 75% ( https://www.theatlantic.com/health/archive/2013/07/the-vitam... ).
I guess we know how to avoid the trouble -- make hypotheses and test them. The trouble there is that the placebo effect is not a bad thing -- if you're doing things which you think will improve your wellness and it works, who cares whether there's a chemical mechanism? It works!
> The trouble there is that the placebo effect is not a bad thing -- if you're doing things which you think will improve your wellness and it works, who cares whether there's a chemical mechanism? It works!
That's an exceptionally oversimplified view on the placebo effect.
There's a very obvious issue: If you take something that helps you due to placebo it may still also harm you due to its side effects. Some vitamins have been shown to increase overall mortality.
But there's another issue, and that is that often what people observe isn't the placebo effect, but something called "regression to the mean". Which is basically the effect that you may take something and you get better, though you would've gotten better anyway, because that's the natural progression of the disease you have. This is very likely a bigger reason for all the "I took it myself and got better, so I know it works!"-stories out there than the placebo effect. And the "who cares why it works?" argument doesn't count for regression to the mean.
> who cares whether there's a chemical mechanism? It works!
There probably even is a chemical mechanism that improves your health. Mental conditions like fear increase your heartbeat, respiration and muscle tonus, being relaxed does the opposite. Stress is a factor we know is contraproductive for the immune system and general health.
The effects have severe limitations of course and I don't think you can take anything to "trigger" the placebo effect. You need the healthy self deception part for it to work.
>As a layperson it feels to me like research in the "megadose on vitamins to prevent illness" area is kind of tainted by the legacy of Linus Pauling
You're completely right, biochemists and medical chemists know fully well it's tainted by Pauling's late work and will tell you so. If even a small positive effect was missed because of that taint, that's a terrible legacy that led to many avoidable deaths (all the people that suffered or died until the positive effect is finally recognized). We should be better at salvaging such effects from their imperfect creators.
4000 IU per day would probably help a lot of people and is still an order of magnitude under the intake that's known to be toxic (60,000 IU/day for several months).
I am a bit perplexed. Haven't almost all randomized/controlled trials shown (e.g. [1]) that there is basically no measurable effect for healthy people? All "positive" stories are relying on observational studies with the usual confounders, right?
EDIT: Look at figure 2 in the Paper. Looks pretty random to me. Result is almost exclusively driven by 4-5 small (<250 participants) and old studies.
D3 is made by irradiating lanolin (from sheep wool) with UV light [1]. Natural source of D3 is oily fish, beef liver. It's the Vitamin D2 that is made from fungi - UV light helps to create it in mushrooms [2].
This is a personal experience. But I've been struggling with constant throat infections, tiredness and coughing every winter for years (I live in a Nordic country). Had my 25-Hydroxy-Vitamin D(D3+D2) checked in both autumn and winter 2 years ago. In October it was ~ 110 nmol/L and in February it was ~ 30 nmol/L. (Deficiency is around 50 nmol/L).
Seeing the seasonal difference was a bit of an eye-opener. And I have been on high dose Vitamin D supplements this winter. And all of my "winter" issues have more or less disappeared.
Yes, I didn't start until late December so I did a little loading with a bigger dose [1]. Next time I'm just going to start around October instead of running into a deficiency.
> When all studies were analysed together, no statistically significant effect of vitamin D was seen on the proportion of participants with at least one upper respiratory tract infection, lower respiratory tract infection, hospital admission or emergency department attendance for acute respiratory tract infection, course of antimicrobials for acute respiratory tract infection, or absence from work or school due to acute respiratory tract infection. However, when this analysis was stratified by dosing frequency, a borderline statistically significant protective effect of daily or weekly vitamin D supplementation against upper respiratory tract infection was seen (adjusted odds ratio 0.88, 0.78 to 1.00; 4483 participants in 11 studies, P=0.05; table 5⇓).
Which to me makes it sound like it makes almost no difference.
Edit: The above could be for pre-exsisting patients.
The paper indicates that a meta-analysis of primary effects in published research shows a significant effect, but for secondary effects in published research (those not related to study aims), no effect. Ok.
Both sorts of reports (of primary and secondary effects) have their own sorts of biases. In general, while there is tendency to only publish and report significant effects (and this applies for both primary and secondary outcomes), study design matters, and a study may not be well designed to detect, or account for other factors, for secondary outcomes- in N, choice of population, control procedures and variables used, or even how accurately and systematically that data was recorded. Does make it hard to evaluate.
Without reading the study in detail, I feel like 4,483 is too few people to detect an effect like this because you can’t easily control for how much vitamin d people get from the sun.
I had a genetic test done (not 23andme or other retail genetic tests) and it turns out I have genes that essentially cause me to have low absorption for vitamins d, b6 and b12 and vitamin e. According to my bloodwork I also had extremely low Vit d in the blood (way below average). I started megadosing and honestly I feel like a different person, when I got a cold before it would last for 7 days, and twice it led to bronchitis and then pneumonia this year since megadosing I’ve had two colds and both lasted no more than 2 days. So I’m not superman, I still get sick but the severity of the colds have been significantly lower than before megadosing.
My B12 deficiency was discovered because of a routine blood test. Low hemoglobin, but since anemia runs in the family the rest was simple enough for my GP to put together.
Eat more red meat (I rarely touched it in the past), and take a daily supplement was the charge. The mental clarity and well-being improvements are palpable.
I can say from my own experience that the lack of vitamin D can have a significant impact on both mind and body.
I suspect that essentially all people living at relatively northern latitudes have some sort of vitamin D deficiency. From what I know you need to have your face and arms exposed to direct sunshine for at least 15 minutes/day to keep healthy vitamin D levels in the body. Good luck with that in the European/Canadian/Northern US winter.
This is one reason arctic people eat so much (vitamin D rich) fish. The other is of course that a plant based diet is impractical when plants are only alive half the year.
White skin itself is an evolutionary adaption for getting enough vitamin D outside of tropical Africa. The extreme "melanin-anemic" blond & blue eyes look of Scandinavia is thought to be because it has a uniquely warm weather for the latitude, which make it possible to grow (vitamin D poor) grains there. That supports by far the biggest population density that far north, but also induces extreme whiteness to soak up every possible sun ray.
Conversely, if you have dark skin and live in the non tropics, you absolutely need to monitor and enhance your vitamin D intake. Sadly, doctors don't seem to bring this up with dark skinned patients, at least from what I hear from my (OK, not that many...) black friends.
I don't have the source handy but there was a geographic point made about Scandinavia that went something like this:
- Scandinavia is very far north and therefore gets less sun in the winter (obviously)
- Apparently the soil of Scandinavia is well suited to crops that are high in Vitamin D
The soil being good for Vitamin D crops (plus lightening of skin/hair and fish diets etc) was a part of why people were able to live in such far northern climates even if they didn't always have access to fish.
> - Apparently the soil of Scandinavia is well suited to crops that are high in Vitamin D
IIUC it's the other way around. soil/climate allows for foods low in Vitamin D -> Vitamin D needed from other sources -> evolutionary pressure for getting it from the sun -> less melanin in skin
I'm probably missing something obvious but... Should white skin not reflect sunlight more, and dark skin absorb it more? I agree that northerners have more need to absorb sunrays and hence make more vitamin D, so shouldn't they be black?
> Should white skin not reflect sunlight more, and dark skin absorb it more?
"White" and "dark" refer to the skin's effects on visible light. Visible light is different wavelengths from UV light; vitamin D production in the skin depends on UV light. "Dark" skin blocks UV light more than "white" skin does.
I think this is how it works: The melanin is not transparent, so it stops the light from penetrating beyond the very surface, and so a smaller volume of skin cells get access to sunlight.
To go a little deeper: Sunlight does two major things in our skin. It creates vitamin D, and destroys folate. Both are essential, so the various skin colors we have reflect the balance evolution has struck in various environments.
Incidentally you can test this yourself: if you go out in the summer you will tan i.e. your skin will darken. This is adaptation to lower the risk of sunburn and skin cancer.
Vitamin D synthesis happens underneath the skin, and requires UV B radiation. The dark skin is an adaptation to avoid UV damage from the normal UV levels you get at the less extreme latitudes by filtering out most of it.
Evolution makes adaptations to what it already has, unlike a sentient designer who might create an optimal design then look for ways to implement it.
If you could design a human from scratch, it might be most efficient to give northerners a D synthesizing pigment that's opaque in the necessary wavelength, resulting in the situation you describe.
Instead we have protective pigments near the surface, synthesizing structures underneath, and a need to balance D synthesis against UV damage.
It's not obvious; this confused me for a long time. The skin we call "white" is fairly transparent to UV, and the skin we call "black" is much less so. Skin is a mixture of transparency and reflectivity at different wavelengths and different depths below the surface. As such it's extraordinarily difficult to model it so it looks right, as any CGI engineer will tell you.
The dark (or not so dark) layer is quite superficial, not far from surface. But the vit D production happens deeper in. For sun rays to get there, that layer must be light-colored.
Sure, some photons do get reflected, but the benefit is from those photons that get deeper into the skin.
Melanin in dark skin doesn't absorb as much UV radiation. It makes sense for people who live under the sun with relatively little protection to be dark skinned but it wouldn't make sense for people who are rarely exposed to the sun to be resistant to it.
Ummm, plants are alive longer than “half the year“. Humans have also preserved foods for out of season consumption for millennia. Natives in California had plenty of plant-based foods in winter months.
Most humans live closer to 27 degrees north of the equator. I mentioned California natives because that’s what I’m most familiar with. Plant preservation is a thing in northern latitudes too..
Natives in California can still be harvesting in November and can see the ground all year round except in the mountains. Natives at the far north might be done with harvesting by late September or early October and might not see the ground again until April. Not even remotely comparable in terms of the severity of the issue and the impact to survival.
Sure, the plants are alive as roots, seeds etc under the snow, but they have nothing edible to offer, so for the purposes of nutrition, they might as well be dead.
Its not possible to get any vitamin D from the sun in the winter in these high latitudes even if you outside in the sun all day with short sleeves. The angle of the sun is too low. We are just beginning march now, so the sun should soon be beginning to be high enough to give some benefit.
Sweden here. My partner is a doctor, she claims with assurance that you can't make a carpet decision like this. People who come from norther latitudes are used to the lack of sun, and their bodies don't need more vitamin D than is provided. Depending on your heritage, ymvm.
That seems implausible. Obviously there was evolutionary pressure on northern Europeans to tolerate lower levels of sunlight and no doubt adaption happened. However, I expect even Swedes evolved in an environment that included more time outdoors than a modern Swedish office worker gets. So, in the absence of any actual evidence, I'd still expect a problem. On top of that, there is some evidence. Basically all the papers found by this search show some evidence of vitamin D deficiency in Swedish people: https://scholar.google.com/scholar?start=10&q=sweden+vitamin...
The first two articles I get from that search looks at vitamin d and the older population, and the third[1] suggests that even in sub-arctic elevations "Adequate levels were found in 79.2%, more often in women (82.7%) than in men (75.6%). Only 0.7% of the population were vitamin D3–deficient but 23.1% of men and 17.1% of women had insufficient levels." That doesn't seem too damning.
At the end of the day I don't know enough, so I'm not making the claim about Vitamin D quantities, but isn't the evidence that there was at least some form of adaptation evident based upon skin tone alone?
I already agreed there was adaption. I just can't see how there can have been adaption for an _indoor_ life at northern latitudes. That's doubly hard, compared to a traditional life in northern latitudes, right? Although, to argue against myself, I guess if you go far enough north, people won't be getting any sunlight in the winter even if they are outdoors all the time. People there must have adapted to that. I guess by eating things with lots of vitamin D.
I love the phrase "carpet decision". Although we don't have it in English, I'm guessing it's roughly equivalent to "blanket statement", something that applies in all cases without exception?
It doesn't work in the binary fashion you described. Low sun angles have two results: Cosine effect and greater atmospheric absorption. The cosine effect decreases the watts per square meter you receive, if your skin is not normal (90 degrees) to the incident sunlight. Greater atmospheric absorption means more UVB is absorbed by the atmosphere before it gets to you, but some still gets through, as anyone who has ever been sunburned in the winter can attest. Higher altitudes and snow on the ground both increase the amount of UVB you receive, even when the sun is low.
getting my blood panel ran and finding out i was deficient in Vitamin D changed my life for the better once i start daily supplementation of Vitamin D3 (5000 IU). I even live in Florida, but working in an office all day doesn't help. Now that my levels are good, i feel as if my memory is far better and i dont feel tired all the time.
There have actually been a couple of studies lately about Vitamin D recommendations being drastically too low. For example [1] recommends 4000 IU/day for adults and [2] recommends 8000 IU/day.
I take about 5000 IU daily (with one or two days off every 10 days or so). I get tested regularly and measure at the top of the lab's 'normal range' (200 nmol/l). I also take vitamin K (especially K2).
I think it depends on the person. If you get your blood level checked when you have a regular physical, you can adjust the dose as needed to keep the level where you want it (I shoot for the upper end of the normal range, and 5000 IU a day seems to be doing that for me).
You can probably play around with the brands and doses a little. I think the important thing is to take gel capsules with oil inside and not solid pills. Vitamin D is fat-soluble so I think solid pills don't get absorbed very well.
There is research showing that the figure of 400 IU is based on a statistical error [1] (that's the original article, there's plenty more if you search).
Most articles I have read recommend somewhere between 2000 and 5000 IUs. Some recommend higher.
The body can produce up to 25000 IU/day in very sunny places on very pale skin. 10000IU/day is considered the safe upper limit. Whether or not that's a good idea long term is a different matter.
The body can produce over 250,000 IU in short order delivered as 25,000 IU a day as a controlled release through the skin. If you want this, the best idea is to spend 5 minutes in your underwear in a tanning bed. Dietary supplements can work, but it takes months.
It actually isn’t. 400 IU is based on preventing disease. To obtain optimal health though, dosages should usually be much higher. Obviously this differs from person to person, but 2000 IU should lead to optimal vitamin D levels. This is an interesting video on the topic: https://www.youtube.com/watch?v=jeLC_b5gDUM
> your face and arms exposed to direct sunshine for at least 15 minutes/day
I wonder what the actual numbers are for this. This weekend, I got out for a couple of 3 hour bike rides, for instance, but it was chilly out, so nothing but my face was exposed.
The first step reaches equilibrium after about 15 minutes in Fitzpatrick type 1 skin in UV index 3-5 (moderate), and about 2 hours in Fitzpatrick type 6. The total amount produced is dependent on the surface area of exposed skin, and the previtamin isomerizes slowly, over about 12 days.
Time to equilibrium is about half the time to acquire sunburn at a UV index high enough to catalyze the previtamin-D reaction. At UV index 6-7 (high), time to burn is about the same as the time to reach previtamin-D equilibrium. At UV index 8 or higher (very high), you will burn faster than you make previtamin-D, and should maybe avoid being exposed during the midday hours. At UV index 11 or higher (extreme), if you are Fitzpatrick type 1, you will carbonize to a burnt matchstick the instant you step out of shadow, like a cartoon vampire, and you should not only not be outside, but should also be huddling in a dark basement waiting on the tyranny of the sun to pass.
Thanks to the equilibrium in the skin, the maximum absorbed dose from sunlight is the equivalent of about 20000 IU per day. High vitamin-D intake also requires increased vitamin-K consumption to reduce calcification of soft tissues.
> you need to have your face and arms exposed to direct sunshine for at least 15 minutes/day to keep healthy vitamin D levels in the body
Even that might not be enough, since in many people the body's ability to synthesize vitamin D when exposed to sunlight decreases with age. The only way to know for sure where you stand is to get your blood levels checked when you get a physical, and supplement if you need to.
As a single, contrary data point, I live in the North of Scotland, and get very little sunlight - I started taking 4,000 IUs a day of vitamin D around a year ago, but haven't noticed any difference whatsoever.
Our modern diets could cause further nutritional deficiencies. I doubt that many people in the West eat fish regularly or supplement with algae oil due to the conveniences of processed food. Same with iodine.
Wheat germs have the highest concentrations in vitamin B1, but whole grains in general (rolled oats etc.) are good so you should probably cut the processed food out as much as possible.
True iodine deficiency is quite rare in the west as many table salts are fortified with iodine. It is extremely uncommon to see people with Goiter in the US. The same goes for thiamine/B1 deficiency which used to cause cardiovascular and neurological disease in alcoholics, but is now very rare becuse many pastas/breads/cereals are fortified with B1.
It can be that there are other hidden deficiencies. Vitamin D was the most surprising for me though because I wasn't aware that you can't really find it in food and that it's only synthesized in the skin in the presence of UV rays.
My biggest surprise: even meat eaters can have Vitamin B12 deficiency.
My doctor recommends all his patients supplement with B12, regardless of whether they're vegetarian, because of the above mentioned potential for everyone to have B12 deficiency, and, according to him, tests for B12 aren't reliable.
I doubt that's the case - for many years when I was a student I lived near equator and never went out. I never felt any impact or mind or body. I even tried some vitamin D3 supplement, smth like 2000IU but had no effects after few weeks, then I quit.
The biggest effect anything I had on me is Testosterone Enthante 250mg twice a week.
Also I wonder if taking 8,000 IU vitamin D can desentivize the system overtime
While my experience is obviously not definitive scientific proof it can still bring some value.
To give you a more simple example: when I broke my leg I went to the doctor's and put it in a cast. That helped me tremendously. Is that a well designed randomized controlled trial? No. Is it good advice to anybody with a broken leg? I would say so.
A cast for a broken leg is not comparable to concluding cause and effect with a vitamin supplement. Vitamin supplement quality, absorption rate, measurement accuracy, etc are all difficult to pin down.
There is science around this though. If you take a vitamin D blood test that shows low levels a doctor will prescribe a certain dose. Vitamin D is scientifically known to be important for humans, it's not just my opinion.
That may be true, but it’s not the same as a broken leg and cast situation, and you need a well controlled randomized trial to say things about cause and effect for non observable phenomena such as the effects of vitamin supplements.
You seem confused as to how science works and what the parent said.
The setup you describe is for proving (with some statistical certainty) a certain causal relationship.
But the author doesn't want to prove it. It has already been proven experimentally. What he said is that he can tell us from his own experience. You don't need a controlled study for that.
I can tell from experience that a certain vitamin X deficiency can be very bad (e.g. because I had it, my doctor verified it, and I got very sick and had Y symptoms) without needing to prove that vitamin X causes Y if it's already proven.
Which is the same case with vitamin D. The parent didn't say he'll prove something novel, just that they'll verify it from experience.
Note that verification from experience is still very useful, even when something isn't proven. It's not as rigorous as science, but it's still very useful, can be life-saving, and it's how civilisation advanced for 1000s of years before we got "controlled studies". People already knew from experience not to eat X or Y plant for example (e.g. poisonous), without official studies and control groups.
People should still be required to be able to make deductions and learn from experience at this level before they offload everything to scientists.
The point of the leg and cast example was to show that anecdotal evidence can be useful. I deliberately chose a clear and simple example. Indeed the case of vitamin D is more nuanced.
I've been wondering why it is that virus infections are supposed to "disappear" in the summer. Obviously the viruses don't actually go anywhere, so I would expect people to get sick year round. Maybe immunity boosting from Vitamin D could be part of the answer.
Mind boggling that this kind of a thing isn't known. This says the total economic effect of seasonal influenza in the US alone is 87 billion per year. That's six NASA:s worth:
Yeah, possible related to sunlight causing dopamine release which inhibits excess growth in the eye, but nothing close to the point of say, public health authorities giving concrete parenting advice based on that.
I like the UV theory, that seasonal decline in UV reduces the chances of virus getting damaged or killed by it. So I'm pinning my hopes on that one to save me from Covad19 because I live in the topices at 400 meter elevation where the UV is pretty brutal year round. Downside, of course, is increased risk of skin cancer.
Research done by National Institute of Child Health and Human Development (NICHD) in 2008 found that the influenza virus has a "butter-like coating". The coating melts when it enters the respiratory tract. In the winter, the coating becomes a hardened shell; therefore, it can survive in the cold weather similar to a spore. In the summer, the coating melts before the virus reaches the respiratory tract.[8]
People spend more time indoors, often with the windows closed. Humidity might also be higher, and temperatures lower, two variables which have an effect on virus viability outside the body.
According to Wikipedia, more time spent indoors is a likely contributing factor to the flu being more active in the cold season, not the other way around.
I take not vitamin supplements at all, drink my Earl Gray with citron and sugar and spend most days of the year in buildings in front of a computer while travelling between them using public transportation. I don't even get enough sleep.
As I personally have a cold quite often I was curious to look into this a bit. Around the same time another metaanalysis was published with a similar question [1], but quite different results (i.e. Vitamin D is unlikely to help).
Here's [2] an (unfortunately only german) article by an austrian webpage associated with the cochrane collaboration (i.e. that should be considered a relatively trustworthy source) that explains this difference due to the fact that the BMJ metaanalysis included many low quality studies that were excluded in the other metaanalysis. This is an indication that this is might be not a real effect, but an artifact of the low quality evidence this analysis is based on.
You don't need vit D if your blood levels are not low, but vitamin d supplements absolutely can raise it if it is low, there is not arguing with that fact. It's established science.
I recall someone telling me you had to be careful of supplementing D or you could promote calcification in arteries. You had to take with a calcium shop or something. Is that true?
Vitamin D has a significant role in calcium homeostasis and metabolism. Its discovery was due to effort to find the dietary substance lacking in children with rickets (the childhood form of osteomalacia).[12] Vitamin D supplements are given to treat or to prevent osteomalacia and rickets.
Can't quote from memory but there is substantial evidence that this is not a problem unless you're taking massive doses (tens of thousands of IU) on a daily basis for a lengthy period. Naturally those interested should check this out for themselves.
Interesting! Anecdotally I used to get very, very bad respiratory infections once a year when working in an office full time, getting at best an hour in the sun a day. Now I remote work and get anywhere from 2-6 hours sun most days, and I haven't had a serious infection for more than a year and a half. Could still be coming, but I feel 200% better overall so regardless, highly recommend getting outside more.
Edit: maybe this came off as a humble brag? Getting a downvote or two, which I don't mind, but I wouldn't want to give off the wrong impression. I only work from home, I am not a jetsetting nomad, I can just work around my outdoor activities now.
I've been taking Vitamin D supplements for a few months. It started after reading a few articles on HN about how the RDA for Vitamin D was too low. Then I came across the NHS guidance which say in effect that everyone should consider taking a Vitamin D supplement, especially those who don't get out in the sunshine much (like most developers). Since there is basically no downside I started taking them.
Anecdotally I feel less lethargic when I remember to take them than when I slip out of the habit. I'm not sure whether that is just the placebo effect but the cost is low enough that it's worth it in either case.
Probably. Or maybe a less stressful commute to work, no crazy office politics, a change in diet/exercise (because you now have time to do those things properly)... It's really difficult to accurately establish correlation let alone causality when it comes to changes in one's health.
Definitely! So many things changed when I went remote that I would never suggest it's entirely down to sun exposure. It would be impossible to say definitively.
Definitely. One of many factors involved. Less commute, always getting enough sleep I am sure help a bunch. But I can also feel a big difference in my abilities when I don't get outside for a few days, even when all those other benefits stay the same.
Very anecdotally but.. I remember my family, 2 adults and 3 kids, going on a two week vacation during the european winter many years ago, and I have been told that none of us were sick in the year afterwards.
In the UK, a science advisory body (Scientific Advisory Committee on Nutrition) published a review of the evidence on vitamin D and health in 2016. Their recommendation: adults and children over one in the UK should take vitamin D supplements in winter.
This advice may not be applicable to people living in sunnier climes. Here is an overview of the guidelines on the NHS website which includes a link to the 300 page scientific review.
Unfortunately I can't find the source, but I read somewhere that it wasn't proven that Vitamin D supplements can improve outcomes after infection has occurred. Can anyone find the source on this and verify?
I unfortunately can't find the source either, but I read something about you having to take vitamin D suppliments for a while before the change could be detected in the body, ie. if you are already sick it does not matter to take suppliments where you only see the benefit after weeks or months. This seems to support what you read.
British Medical Journal? Impact factor 27.604 in 2018. But in scientific publishing the intended audience is not lay people. You really have to know how to read the articles to determine what they mean. I liked their series of articles called "How to Read a Paper."[0] But keep in mind [1].
This is a well-written meta analysis in a top-tier medical journal which demonstrates a convincing relationship between acute respiratory infection, Vit D baseline levels, and supplementation.
However, their conclusion that the findings warrant public health interventions and widespread supplementation is arguable. There are real risks and costs to over-supplementation, and the absolute risk reduction they demonstrate (from 42% to 40%) is not large.
According to Wikipedia: “ As of 2008, the five journals that have been cited most frequently by articles published in The BMJ are The BMJ, The Lancet, The New England Journal of Medicine, Journal of the American Medical Association and Cochrane Database of Systematic Reviews.” So your statement is quite incorrect or you are being sarcastic.
So cold viruses do better in cold weather and in northern latitudes with fewer sunlight hours we may expect the combination to result in more cold in winter time?
I don't recall any anger. Hacker News is in the 'focus on facts' phase of responding to mass panic, and I believe we won't move on to the 'resignation' phase anytime soon.
Huh, the only comments I saw about "megadosing" were explicitly refuting the notion of megadosing vitamin C, and the effect that that quackery has had on the science. Are we reading the same comments?
This year I started supplementing with 2000 UI of vitamin D daily and it's as if my immune system started functioning normally, in the last 10 months I only caught a really light cold that I could barely notice, whereas before this the winter season alone would bring 2 severe cold or flu episodes that would knock me down for several days.
I can't really say if it's the vitamin D, or other changes in my life, like losing some weight or walking more, or the cold exposure I've been practicing (primarily because I heard it burns calories :-)), it might be even placebo, I haven't isolated these variables well, but my wife and close ones are amazed by the transformation. E.g. 3 weeks ago everyone in my household got the flu, except for me.
So now I got everyone in my household on vitamin D, especially b/c of this coronavirus scare. During summer time we might not need it, but the sun doesn't see us during winter. And vitamins are probably no defense against the coronavirus, but a deficiency could amplify the damage (as vit D has a role in our immune system) so it's best to ensure that we aren't deficient. Also we tolerate large doses of vitamin D, so it can't hurt.