Vitamin D has been shown to reduce severity in several different studies. Everyone should consider taking it.
https://www.reddit.com/r/COVID19/search?q=vitamin+D&restrict...
https://www.reddit.com/r/COVID19/search?q=vitamin+D&restrict...
https://www.medrxiv.org/content/10.1101/2020.11.16.20232397v...
(Yes, the RCT uses cholecalciferol instead of calcifediol, so the reason why the intervention did not work may be that its a bit late. Yes, the Spanish trial had extremely good results, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456194/ but it looked unusual (100% adherence / no dropouts). Ultimately we still don't know, which is appalling. We need better ways to conduct RCTs cheaply and efficiently!)
My point is that its important for people to have an accurate picture of what is the probability of it working, to have a good "feel" of what the likelihood of a good outcome is. Unfortunately social media is providing a skewed picture.
I'm not sure what mechanism would ensure that people get an accurate picture.
To be clear, if you live in the northern hemisphere, you should be taking vitamin D. It's cheap and at worst harmless. But that's not the same as saying it will improve the outcome of covid patients.
Oral vitamin D has been shown to be ineffective at this point, but this isn't surprising: it takes a long time of sustained oral supplementation to raise levels.
Then there's a whole lot of evidence showing correlation, but as you point out, low vitamin D is an indicator of frailty. This is much weaker evidence.
I think it's likely that taking oral vitamin D before infection probably improves outcomes somewhat.
> Of 50 patients treated with calcifediol, one required admission to the ICU (2%), while of 26 untreated patients, 13 required admission (50 %) p value X2 Fischer test p < 0.001.
Strengths: Randomized, very strong effect, strongly statistically significant.
Weaknesses: single trial, single center, relatively small sample, not blinded.
https://pmj.bmj.com/content/early/2020/11/12/postgradmedj-20...
> Greater proportion of vitamin D-deficient individuals with SARS-CoV-2 infection turned SARS-CoV-2 RNA negative with a significant decrease in fibrinogen on high-dose cholecalciferol supplementation.
Strengths: Randomized, blinded trial
Weaknesses: single trial, single center, relatively small sample, secondary outcome measure
Half true, you can take too much [0], it's just that it either has to build up over a long time or be from dosages far larger than you can buy without a prescription.
[0] https://www.healthline.com/nutrition/vitamin-d-side-effects
https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-... https://www.nhs.uk/conditions/coronavirus-covid-19/people-at...
So can the conclusion be that vitamin D does not work as expected? Or is the conclusion that still not enough people are taking vitamin D, and its usefulness should be better communicated?
Vitamin D has shown signs that it slows down / makes covid less deadly.
Because we don't understand: who is taking it, in what amounts, local weather, what the numbers would be without it we can't assume anything from them struggling.
Another thing that is tricky is that it really depends how much you need to take on what your levels are personally. We know that the amounts they recommend are completely long term safe for everyone and long term good enough to avoid severe deficiency. But for most people there will still be insuficiency - the necessary average is actually around 2000 IU (for some people it should be up to 4000 IU, others less)
Are you saying the NHS is struggling with their doctors publishing dangerous recommendations? I’m not sure what you’re implying.
> Just over two-thirds of Canadians (68%) had blood concentrations of vitamin D over 50 nmol/L -- a level that is sufficient for healthy bones for most people. About 32% of Canadians were below the cut-off. About 10% of Canadians were below the cut-off of 30 nmol/L -- a level that is considered a deficiency.
In Canada, everyone is advised to discuss it with their doctors in relation to the winter season. My doctor tests it with my routine blood work. Many people take a supplement over the winter, especially those with darker skin. And people over 50 have a blanket recommendation to take a 400 IU dose daily year-round.
Deficiency of vitamin D is immune system dysfunction.
There's no single answer. Vitamin D is basically a panacea, but for some reason most medical professionals don't know. Modern western medicine is on the whole ignorant of the role of vitamin deficiencies in disease.