Vitamin D doesn't prevent COVID-19, other respiratory infections, studies find

[onthedarkside]

 

Findings from two large clinical trials published yesterday in BMJ discount the notion that vitamin D supplements protect against COVID-19 or other respiratory-tract infections, although both had notable limitations.

...

"Among people aged 16 years and older with a high baseline prevalence of suboptimal vitamin D status, implementation of a population level test-and-treat approach to vitamin D supplementation was not associated with a reduction in risk of all cause acute respiratory tract infection or COVID-19," the authors wrote.

...

In Norway, a team led by Oslo University researchers studied whether low-dose vitamin D supplementation in the form of cod liver oil in winter would prevent COVID-19 infection, serious illness, or other respiratory infections in adults not already taking the vitamin.... Cod liver oil was not tied to a reduced risk of COVID-19 infection, serious illness, or other respiratory infection.

...

In a related editorial, Peter Bergman, PhD, of the Karolinska Institutet in Sweden, said that the findings of both trials could have been skewed by the concurrent "highly successful" COVID-19 vaccine rollout in the United Kingdom and Norway.

 

(more)

 

https://www.cidrap.umn.edu/news-perspective/2022/09/vitamin-d-doesnt-prevent-covid-19-other-respiratory-infections-studies-find

 

 

UK:

https://www.bmj.com/content/378/bmj-2022-071230

 

Norway:

https://www.bmj.com/content/378/bmj-2022-071245

 

[onthedarkside]

A post with entirely unsourced claims has been removed.

 

[internationalism]

267 000 scholarly articles on the subject. Probably most of them contradicting that one.

Take you pick.

https://scholar.google.co.th/scholar?q=Vitamin+D+COVID-19&hl=en&as_sdt=0&as_vis=1&oi=scholart

[onthedarkside]

31 minutes ago, 300sd said:

Dr. Fauci takes 6000 IU of Vitamin D in the winter. Wonder why? He said this in an interview almost 2 years ago. Go figure.

 

The two studies cited above DON'T say there's no reason to take Vitamin D in general.

 

But they DO say, taking it won't help prevent getting COVID or reduce the symptoms of COVID.

 

As for Fauci...

 

https://www.cnbc.com/2020/09/14/supplements-white-house-advisor-fauci-takes-every-day-to-help-keep-his-immune-system-healthy.html

 

"During another interview with actress Tiffany Haddish released on Sept 4 [2020]., Fauci said in clinical studies most “so-called” immune-boosting supplements didn’t really help people unless they had some sort of a deficiency. In fact, a lot of these herbs “either do nothing, or, if you take too much of them, they harm you,” Fauci told Haddish."

 

But the same article does mention:

 

"(In fact, researchers at the University of Chicago Medicine recently found a link between vitamin D deficiency and the likelihood of being infected with Covid-19 — those with an untreated deficiency were more likely to test positive. “Vitamin D is important to the function of the immune system and vitamin D supplements have previously been shown to lower the risk of viral respiratory tract infections,” David Meltzer, chief of hospital medicine at UChicago Medicine and lead author of the study said in a press release on Sept. 8.)"

 

[onthedarkside]

22 minutes ago, internationalism said:

267 000 scholarly articles on the subject. Probably most of them contradicting that one.

Take you pick.

https://scholar.google.co.th/scholar?q=Vitamin+D+COVID-19&hl=en&as_sdt=0&as_vis=1&oi=scholart

 

Here's the findings of one of the studies in your list, a recent one from Jan. 2022:

A critical update on the role of mild and serious vitamin D deficiency prevalence and the COVID-19 epidemic in Europe

Highlights

"There is not sufficient data to associate vitamin D prevalence with the COVID-19 epidemic in Europe.

 

Vitamin D supplementation cannot be recommended as a preventive measure against COVID-19 infection.

 

Mortality due to COVID-19 infection can be influenced by several parameters of an individual's health; therefore, further research is needed to state that vitamin D deficiency can be related with COVID-19-specific mortality."

 

https://www.sciencedirect.com/science/article/pii/S0899900721003038

 

At the least, the notion of Vitamin D supplementation as a measure to fight COVID seems to be quite an unsettled issue.

 

 

[Lorry]

Actually,  recently a study was published saying that Vit D isn't good for anything.  Something many people suspected all along.  NYT reported about 4 weeks ago, sorry, i don't have time to search.  Supposedly the first really good study.

 

The NYT also explained how Vit D is big business (selling, testing).

Edited September 9, 2022 by Lorry

[Padthaigoong]

Don't tell me

Vaccination is the only answer.

[BangkokHank]

9 hours ago, Lorry said:

The NYT also explained how Vit D is big business (selling, testing).

Vitamin D is free - from the sun. And you don't think vaccines are big business? Ha.

[internationalism]

as I couldn't find this article "A critical update on the role of mild and serious vitamin D deficiency"

within the first few pages sorted by relevance, I have searched by date.

That one is from a week ago - based on 38 studies involving over 200k patients.

Problem is, that many are vit D deficient, even in Thailand.

A small dose of fish oil in the first study contained not enough vit D to make a significant impact. A large dose might.

btw - during pandemic, and until now, I am taking calcium, which happen is boosted in my supplement with Vit D. But the most important factor is not food and even not supplement, but daily sunshine - some 20 minutes and sufficient on face and arms.

 

"A growing body of epidemiological evidence suggests that low 25-hydroxy vitamin D (25-OH-vitamin D) plasma levels are associated with an increased risk of developing COVID-19 and —most importantly—with a higher risk of developing more severe COVID-19 and dying. On the other hand, vitamin D supplementation during the early phases of COVID-19 has been related to a decreased length of hospital stay, less frequent need for oxygen, and a reduced mortality rate in inpatients. This seems to be particularly true when high dosages are used. In light of this evidence, further studies are needed to define the best timing for vitamin D supplementation and the most effective dosage schedule."

"Vitamin D Supplementation and COVID-19 Outcomes: Mounting Evidence and Fewer Doubts"

https://www.mdpi.com/2072-6643/14/17/3584/htm

 

 I was forced to hospitalise for a very mild omicron in thailand, on entry from europe. I would expect some vit to be prescribed, starting from vit C. Instead, I was prescribed antiviral for 350b per pill (and I supposed to take 9 pills per day for many days), but I have refused such rip-off. Instead, my wife passed me 1 litre of freshly made lime juice, a litre of honey, 2kg of natural youghurt, several kg of fruits. I have exposed myself to sunshine by opening window for all the time it was shining on my part of building. Even at private hospital I had problem choosing menu with fresh fruits and vegetables (avoiding rice and starch)

Edited September 10, 2022 by internationalism

[retiree]

The July 27 2022 NYTimes article (legally unlocked): 

 

Source link:

 

They note that:

Labs in the United States then arbitrarily set 30 nanograms per milliliter as the cutoff point for normal vitamin D levels, a reading so high that almost everyone in the population would be considered vitamin D deficient.

 

The main study (called VITAL) the NYTimes points to is here:

 

https://www.nejm.org/doi/full/10.1056/NEJMoa2202106 

 

CONCLUSIONS
Vitamin D3 supplementation did not result in a significantly lower risk of fractures than placebo among generally healthy midlife and older adults who were not selected for vitamin D deficiency, low bone mass, or osteoporosis.

 

A second double-blind study of 20,000 older Australians they point to is (emphasis mine):

 

https://www.thelancet.com/journals/landia/article/PIIS2213-8587(21)00345-4/fulltext 

 

Administering vitamin D3 monthly to unscreened older people did not reduce all-cause mortality. Point estimates and exploratory analyses excluding the early follow-up period were consistent with an increased risk of death from cancer. Pending further evidence, the precautionary principle would suggest that this dosing regimen might not be appropriate in people who are vitamin D-replete.
 

I'll mention in passing that this is exactly what happened with the antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) studied in this well-known paper (a review of seventy-eight randomised trials with 296,707 participants) -- they did not extend, and in some cases reduced, life span: 

 

https://pubmed.ncbi.nlm.nih.gov/22419320/ 

 

Back to vitamin D, the editorial in the New England Journal of Medicine the Times points to says (emphasis mine):

 

https://www.nejm.org/doi/full/10.1056/NEJMe2205993

 

VITAL Findings — A Decisive Verdict on Vitamin D Supplementation

... 

More than 10 million serum 25-hydroxyvitamin D tests are performed annually in the United States. Results from these tests often include the classification of vitamin D “insufficiency” (<30 ng per milliliter) and “deficiency” (<20 ng per milliliter), prompting vitamin D supplementation. In this ancillary study and other VITAL studies, no subgroups defined according to baseline 25-hydroxyvitamin D level, even below 20 ng per milliliter, benefited from supplements.2,3,7 Thus, there is no justification for measuring 25-hydroxyvitamin D in the general population or treating to a target serum level.   ... 
                      

What are the implications of VITAL? The fact that vitamin D had no effect on fractures should put to rest any notion of an important benefit of vitamin D alone to prevent fractures in the larger population. Adding those findings to previous reports from VITAL and other trials showing the lack of an effect for preventing numerous conditions suggests that providers should stop screening for 25-hydroxyvitamin D levels or recommending vitamin D supplements, and people should stop taking vitamin D supplements to prevent major diseases or extend life.

 

-- Retiree                  

[onthedarkside]

A post linking to a website promoting debunked, disallowed treatments for COVID has been removed.

 

 

[AddyA]

I'm not sure what point the OP is trying to make with their headline. Vaccinations don't prevent COVID-19, either. However, multiple research has proved that adequate levels of vitamin D—like vaccinations—reduces the risk of severe COVID-19. 
 

Here's an extract from 2022 research;
 

Feb. 8, 2022: People with a vitamin D deficiency are more likely to have a severe or critical case of COVID-19, according to a new study published in the journal PLOS ONE.
 

Patients with a vitamin D deficiency, were 14 times more likely to have a severe or critical case of COVID-19. What’s more, the mortality rate for those with insufficient vitamin D levels was 25.6%, compared with 2.3% among those with adequate levels. 

Source: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0263069 

[onthedarkside]

13 minutes ago, AddyA said:

I'm not sure what point the OP is trying to make with their headline. Vaccinations don't prevent COVID-19, either. However, multiple research has proved that adequate levels of vitamin D—like vaccinations—reduces the risk of severe COVID-19. 
 

Here's an extract from 2022 research;
 

Feb. 8, 2022: People with a vitamin D deficiency are more likely to have a severe or critical case of COVID-19, according to a new study published in the journal PLOS ONE.
 

Patients with a vitamin D deficiency, were 14 times more likely to have a severe or critical case of COVID-19. What’s more, the mortality rate for those with insufficient vitamin D levels was 25.6%, compared with 2.3% among those with adequate levels. 

Source: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0263069 

From the study you cited:

 

"while our findings have identified an association between pre-infection vitamin D deficiency and COVID-19 severity, these results do not necessarily imply that vitamin D treatment will impact COVID-19 outcomes. Therefore, we should remain cautious about overestimating the potential benefit of vitamin D supplementation in improving outcomes of SARS-CoV-2 infection."

...

"Our study warrants further studies investigating if and when vitamin D supplementation among vitamin D deficient individuals in the community impacts the outcome of an eventual COVID-19 episode."

 

[retiree]

The problems with observational studies (including this one in PLOS) in general, are that:
 - they report on correlation, not causation,
 - they do not investigate the entire population, i.e. why do other people with low vitamin D not have Covid-19?
 - it is very difficult to rule out confounding (simultaneous or parallel) variables that might be the actual cause.  Thus ...
 - the observed variable (in this case vitamin D) may itself be a symptom of a shared cause.

 

The PLOS authors are entirely forthcoming in pointing this out; see the "important limitations of the study" section (last two paragraphs of the Discussion)

First, vitamin D deficiency can be one indication of a wide range of chronic health conditions or behavioral factors that simultaneously increase COVID-19 disease severity and mortality risks. 

 

This is how good science works -- you strengthen your case by raising the strongest possible arguments against it.  A few paragraphs before they also note that:  
A recent study suggested an association between UVA or UVB exposure to COVID-19 disease severity independent of vitamin D [34].

That reference [34] says:
https://academic.oup.com/ajcn/article/115/4/1123/6448988
Our data also support an association between exposure to UV-B or UV-A, independently of vitamin D and SARS-CoV-2 infection, so results for predicted 25(OH)D need to be interpreted cautiously.

[34] also points to this editorial, which discusses possible causation:
https://academic.oup.com/ajcn/article/115/4/987/6530387
Putative roles of solar UVA and UVB exposure and vitamin D supplementation in reducing risk of SARS-CoV-2 infection and COVID-19 severity
3 mechanisms seem to be related to solar UV exposure:  vitamin D production, NO liberation [nitrous oxide, I assume], and viral inactivation.

 

The PLOS article also points to this note, whose title is self explanatory:
Letter to the Editor: Vitamin D deficiency in COVID-19: Mixing up cause and consequence
https://www.metabolismjournal.com/article/S0026-0495(20)30298-5/fulltext

 

Finally, the PLOS article has a long series of references (26 - 37), that study Arab populations in general to investigate possible cultural and genetic reasons for the "high percentage of vitamin D deficiency among Israeli Arabs" (although their own data "showed no effect of ethnicity on disease severity and mortality").  These other studies discuss factors that that may engender susceptibility to Covid-19 in parallel with, rather than being the result of, low vitamin D.  

 

Again, let me reiterate the central weakness of studies like the PLOS article.  I take it at face value that

  a lower vitamin D status was more common in patients with the severe or critical disease.  

But I also recognize that whenever a doctor advises a non-Covid, low vitamin D patient to take a supplement, and also to get a little more fresh air, sunshine, and exercise, s/he is also demonstrating just how easily confounding variables may undermine observational studies.

 

-- Retiree
                                                                                                                                                      
 

Edited September 10, 2022 by retiree

[AddyA]

3 hours ago, onthedarkside said:

From the study you cited:

 

"while our findings have identified an association between pre-infection vitamin D deficiency and COVID-19 severity, these results do not necessarily imply that vitamin D treatment will impact COVID-19 outcomes. Therefore, we should remain cautious about overestimating the potential benefit of vitamin D supplementation in improving outcomes of SARS-CoV-2 infection."

...

"Our study warrants further studies investigating if and when vitamin D supplementation among vitamin D deficient individuals in the community impacts the outcome of an eventual COVID-19 episode."

 

You are correct,  and most studies err on the side of caution with preliminary findings. And I also understand the conflicts between correlation and causation. But even so, it would be somewhat naive to discard those findings as rubbish based on the above. 
 

Here's a quote from Amiel Dror, MD, the lead study author and a doctor at Galilee Medical Center.
 

"We found it remarkable, and striking, to see the difference in the chances of becoming a severe patient when you are lacking in vitamin D compared to when you're not." 
 

He goes on to say....
 

“We checked a range of timeframes and found that wherever you look over the 2 years before infection, the correlation between vitamin D and disease severity is extremely strong,” Dror told The Times of Israel. “It emphasizes the value of everyone taking a vitamin D supplement during the pandemic, which, consumed in sensible amounts in accordance with official advice, doesn’t have any downside.”

 

Edited September 10, 2022 by AddyA

[onthedarkside]

1 hour ago, AddyA said:

Here's a quote from Amiel Dror, MD, the lead study author and a doctor at Galilee Medical Center.

I was scratching my head, just a bit, wondering what a bunch of ear, nose and throat doctors (ENTs) were doing writing a study relating to Vitamin D and COVID....

 

From the study's info section on its authors:

 

 

[MrJ2U]

On 9/9/2022 at 9:29 PM, 300sd said:

Dr. Fauci takes 6000 IU of Vitamin D in the winter. Wonder why? He said this in an interview almost 2 years ago. Go figure.

 

No source.

 

Because it's not true. 

[MrJ2U]

3 minutes ago, BangkokHank said:

 

Hopefully he cuts down now that it's been proven useless against COVID.

 

Older people though it's good for the bones supposedly. 

 

At that amount its almost toxic. 

 

"The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones."

 

https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-d-toxicity/faq-20058108#:~:text=The main consequence of vitamin,the formation of calcium stones.

 

 

I'm out in the sun and drink plenty of milk.  Plenty of natural Vitamin D, the best. 

 

[BangkokHank]

On 9/10/2022 at 10:31 PM, MrJ2U said:

Hopefully he cuts down now that it's been proven useless against COVID.

 

Ha. At first you said that there was no evidence that Fauci takes vitamin D, and after I provided the evidence, you are now saying that you hope he cuts down his use of it?

Edited September 12, 2022 by onthedarkside
flame comment removed

[MrJ2U]

On 9/10/2022 at 10:48 PM, BangkokHank said:

Ha. At first you said that there was no evidence that Fauci takes vitamin D, and after I provided the evidence, you are now saying that you hope he cuts down his use of it?

"When you talk about the multiple multivitamins and the herbs and the things that people do to so-called boost immunity, that really doesn't boost immunity and may have a better placebo effect than anything else," Fauci said. "

 

"Fauci will still say, without question, the best ways to control the pandemic are the measures he's been recommending endlessly for months: good hand hygiene, mask-wearing, and social distancing."

 

https://www.businessinsider.com/fauci-3-tips-keep-your-immune-system-strong-vitamins-sleep-2020-9

[mommysboy]

23 hours ago, Padthaigoong said:

Don't tell me

Vaccination is the only answer.

Yes, well that and of course your own immune system. 

 

Wouldn't put my faith in anything else, save keeping in shape.

 

I was surprised aspirin didn't help with symptomatic infection.

 

[mommysboy]

On 9/10/2022 at 10:51 PM, rattlesnake said:

 

 

You can keep your immune system healthy, but it's not possible to boost it beyond that as such. 

 

I didn't get symptomatic covid infection until a month ago.  My family had it four months ago and I was surrounded by the virus at that time in a confined space for hours on end. It's the nature of these things- nothing happens until one day it happens.  My best guess would be you have been infected on at least one occasion, maybe multiple times. Possibly you had a similar virus many moons ago and your immune system is wise to it.

[rattlesnake]

On 9/10/2022 at 11:39 PM, mommysboy said:

 

You can keep your immune system healthy, but it's not possible to boost it beyond that as such. 

 

I didn't get symptomatic covid infection until a month ago.  My family had it four months ago and I was surrounded by the virus at that time in a confined space for hours on end. It's the nature of these things- nothing happens until one day it happens.  My best guess would be you have been infected on at least one occasion, maybe multiple times. Possibly you had a similar virus many moons ago and your immune system is wise to it.

I think you're probably right. And actually my above statement is incorrect, I was unwell for a few hours about 5 months ago. Woke up at about 5 am with flu-like symptoms, chills and muscle pain (but no cough), I couldn't get out of bed, even reaching for my phone was a challenge. At about 11 am I started to feel better, at noon I was up, felt a bit tired all afternoon and in the evening I felt normal again. So perhaps I did briefly interact with Covid.

 

Edited September 12, 2022 by onthedarkside
unsourced misinfo claim removed

[rumak]

On 9/10/2022 at 10:51 PM, rattlesnake said:

 

My experience almost exactly the same ( and mrs rumak ) .    All my "vaccinated" friends have gotten covid , though they often say "might have been worse"   .   On the other hand,  MAYbE   if they had followed a healthy regimen like rattlesnake, myself, and a few other non vaxxed friends...... they would not have been sick at all .

 

 

 

[AddyA]

11 hours ago, onthedarkside said:

I was scratching my head, just a bit, wondering what a bunch of ear, nose and throat doctors (ENTs) were doing writing a study relating to Vitamin D and COVID....

 

From the study's info section on its authors:

 

 

It's no different to the many non-PPE experts informing the public on Mask Science. Yet millions took (and continue to take) their word on the efficacy of masks.
 

But regardless of the messenger/researcher, what I posted above is either true or it's not, and that's the point. Perhaps your response would have made more sense if you tried to disprove the above evidence, if indeed you do disagree with those findings?
 

[mommysboy]

On 9/11/2022 at 9:47 AM, rumak said:

My experience almost exactly the same ( and mrs rumak ) .    All my "vaccinated" friends have gotten covid , though they often say "might have been worse"   .   On the other hand,  MAYbE   if they had followed a healthy regimen like rattlesnake, myself, and a few other non vaxxed friends...... they would not have been sick at all .

 

 

Frankly that doesn't stand any scrutiny. 

 

The important factors are length, duration, and amount of viral exposure, and any prior immunity.

 

One thing we know is that nearly everyone gets colds/flu/upper respiratory viral infections- young, old, healthy, and unhealthy.  Indeed, healthy people are more likely to get out and about and pick up colds, and also go to school, etc.  I'm not sure that having a health regime even prevents you from getting a real 'stonker' of a cold- some professional football teams have been known to cancel matches when a virus strikes.

 

It doesn't matter so much with Omicron whether you get vaccinated or not. Personally, I think it's a sensible precaution above 50. 

[AddyA]

14 hours ago, MrJ2U said:

No source. Because it's not true. 

This is a perfect example of how you can find anything to support any argument on any topic from credible sources if you look for it.
 

So who's right? Person A, who chooses to believe the views of one set of experts, or person B, who thinks the results of other experts are correct? 
 

There is no right or wrong answer until research is proven true without question or doubt. But, unfortunately, most of it isn't, and there lies the problem. But the "I'm right, and you're wrong" response can never be a part of an intelligent debate when there is no definitive answer.

[Gecko123]

15 hours ago, MrJ2U said:

'm out in the sun and drink plenty of milk.  Plenty of natural Vitamin D, the best. 

Not sure where you're located, but milk in Thailand is generally not fortified with Vitamin D as it is in many Western countries. Unfortified milk is actually low in Vitamin D.

 

Not going to wade into the Covid-19 debate, but have read that high percentages of the population have a Vitamin D deficiency and there are lots of non Covid-related benefits to monitoring Vit D intake.  Have been taking cod liver oil and eating more canned fish in past 2 years after discovering dairy in Thailand was not fortified.

 

https://www.healthline.com/nutrition/vitamin-d-milk

Edited September 11, 2022 by Gecko123

[Neeranam]

Don't believe a word, I'm going out to the pool. 

[retiree]

19 hours ago, AddyA said:

Dror told The Times of Israel. “It emphasizes the value of everyone taking a vitamin D supplement during the pandemic, which, consumed in sensible amounts in accordance with official advice, ..."

I don't think anybody discards the PLOS study.  And I think Dr. Dror's advice is sensible at all times:  if you have low sun exposure (common in Israel), and don't take vitamins or drink vitamin D fortified milk (not mandated in Israel, or Thailand either), then it's a good idea to follow the "official advice" of the Israeli government (and the WHO, US, and many others) on vitamin D supplements:  600 IU/day (800 IU if over 70).  Dr. Dror is also a strong proponent of masking and vaccination (from age 5 on up), btw.   

 

However, I suspect that most readers have very little interest in what the doctors and scientists who wrote the PLOS paper actually have to say (beyond the headlines).

 

The paper shows a correlation between very low vitamin D levels in Israel (where this is common -- 64.3% of the Israeli Arab population, which the paper focused on, have < 20ng/mL), and more severe Covid-19.   Some people then might then make a series of unsupported assumptions:

 

 - a subgroup of Israelis with low vitamin D levels have severe Covid-19,
 - people with severe Covid-19 everywhere might also have low vitamin D levels,
 - Covid-19 might be common because low vitamin D is common (up to 80% of some national populations are called "insufficient"),
 - if very low levels are bad, then high levels might very well be protective,
 - if high levels are protective, perhaps they're just as good as vaccines, which are also "just" protective against severe disease.
 - a though might occur that maybe one could take vitamin D instead of getting vaccinated,  
 - indeed, maybe if everybody took vitamin D, they'd all be protected and we wouldn't have a Covid-19 epidemic -- maybe "herd high vitamin D" levels could stop these diseases entirely. 

 

Now, my impression is that takes some effort (or disability) to have dangerously low vitamin D levels, of which the most obvious consequence is rickets (which I doubt any of us have ever encountered).  

 

It is estimated that in London (which closer to the North Pole than Calgary in Canada is, mind you), fairly white Caucasians need about 9 minutes of mid-day sun exposure (baring hands and face in winter, and arms and shins in warm weather); they estimate 25 minutes for fairly dark-skinned people.  And most daily multi-vitamins have several hundred IU (Centrum Silver has 1,000, ordinary Costco / Kirkland Daily Multi has 400 IU), and fortified milk has 400 IU or more per liter.

Meeting Vitamin D Requirements in White Caucasians at UK Latitudes
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5946282/   
https://www.bytemuse.com/post/interactive-equivalent-latitude-map/   (scroll down a bit to see it).

 

Nevertheless, the VITAL tests -- double-blind RCTs -- show that it is very easy to have levels that are called "insufficient" (up to 80% of the population!) but do not seem to have any health impact that is improved by vitamin D supplements, even when combined with calcium.  That's why the New England Journal of Medicine last month advised to stop calling the 20-30 ng/ml range "insufficient,"

 

https://www.nejm.org/doi/full/10.1056/NEJMe2205993

VITAL Findings — A Decisive Verdict on Vitamin D Supplementation

... there is no justification for measuring 25-hydroxyvitamin D in the general population or treating to a target serum level.   ...  people should stop taking vitamin D supplements to prevent major diseases or extend life.

 

-- Retiree

Edited September 11, 2022 by retiree