[ralala]

Could it be that just both, vitamin D deficiency and covid-19 risk, are much higher for people that stay inside most of the day (e.g. have office jobs)? Vitamin D is created from sunlight. Covid-19 is transmitted by aerosols. Is there additional evidence that Vitamin D supplements may help or do we just know about the correlation?

[navi0]

This recently published study suggests vitD supplements alone provide some protection, even for acute cases. It’s a small sample population (n=75) and a pre-print, but it looks convincing to me (non-scientist, non-medical professional):

“Of 50 patients treated with calcifediol, one required admission to the ICU (2%), while of 26 untreated patients, 13 required admission... Of the patients treated with calcifediol, none died, and all were discharged, without complications. The 13 patients not treated with calcifediol, who were not admitted to the ICU, were discharged. Of the 13 patients admitted to the ICU, two died and the remaining 11 were discharged.”

https://www.sciencedirect.com/science/article/pii/S096007602...

Previous HN discussion: https://news.ycombinator.com/item?id=24390451

[acqq]

That link has only one comment. Actual discussion with 390 comments is:

https://news.ycombinator.com/item?id=24366006

and my comment there:

https://news.ycombinator.com/item?id=24366933

In short, my problem with that paper is:

"The whole paper contains neither raw data nor any graphs and only means and standard deviations"

Given small number of people in the study, it's not clear that there aren't some problems that aren't visible when reporting the means which would be obvious when looking at the actual data.

Even the randomized studies aren't "true" automatically: the process of randomization can have issues itself, and that should be also possible to check.

[acqq]

The study from the title is indeed just a correlation, from the abstract:

"This study used a retrospective, observational analysis of deidentified tests performed at a national clinical laboratory."

Whenever you see a "retrospective, observational" related to anything having to do with medicine or biology, consider that the experts seldom see that as a proof of anything, but only a hint to a possible hypothesis that could be investigated in some other way (and then confirmed or rejected).

As another example that correlation doesn't mean causation, even if the paper is published about the correlation, see:

https://youtu.be/UHDi6tNMHyU?t=2780

That "bald men and Covid-19" study did not control for age (where the older people are more probable to be both more bald and have worse outcome, making correlation not saying much when that is not controlled for), this study seems didn't control for "staying inside most of the day" or even "inside with more people" etc. Good catch.

[spurgu]

I know very little about nutrition but have wondered whether taking supplements actually help, or if it's the process that _creates_ those vitamins that's actually important/healthy.

Like in your example, being exposed to sunlight starts a process in our body that's healthy for our bodies, and vitamin D is just a by-product... and taking it as supplements wouldn't really do anything as we're missing the process.

As I said I have no idea what I'm talking about.

[heavyset_go]

> if it's the process that _creates_ those vitamins that's actually important/healthy.

By definition, vitamins are substances needed by an organism that it can't create itself, and must be obtained in its diet.

[jwilk]

Vitamin D is technically not a vitamin:

https://academic.oup.com/ajcn/article/88/2/491S/4649916#1112...

[dehrmann]

Vitamin D is arguably not a vitamin because we produce it when exposed to sunlight and it's actually a hormone. I guess that makes sunlight the vitamin.

[0_____0]

vit D is an exception here, iirc it's the only 'vitamin' that doesn't fit those criteria

[rossdavidh]

It could easily be some of both, in which case a supplement is not necessarily worthless, but not as good as sunlight (and the exercise and stress reduction that often goes with it).

[scythe]

>Is there additional evidence that Vitamin D supplements may help or do we just know about the correlation?

Yes. COVID-19 is known to affect the renin-angiotensin-aldosterone signalling cascade. Vitamin D is also known to be involved in this signalling. That's why speculation about vitamin D is more than just statistical hokum.

There is the chance of an error, but there is also a clear indicator for an underlying mechanism here.

[takeda]

I thought so too, but looks like there's difference even among kids. Kids with darker skin are more affected than their peers with lighter skin.

[cwwc]

Brilliant thought, though I hope it is untrue.

[kebman]

Well, there's this article, also posted earlier on HN: https://www.devaboone.com/post/vitamin-d-part-3-the-evidence...

My personal experience with Cod Liver Oil (usually taken in Norway due to its high contents of Vitamin D) is that it really helps against dry lips. But you get a rather fishy breath from it...

[jusssi]

You can get it in capsules. That should solve any taste and smell problems.

[ComputerGuru]

It depends. Some people still find them to be too fishy, but I’ve heard storing the plastic pill bottle in the freezer and downing them frozen can further mitigate the fishiness and reduce fishy reflux.

[TheRealPomax]

Could? Sure. But let's not start second guessing the science until after reading the full publication, especialy the part where the correlation is observed across all latitudes, which gives a fairly solid spread of sunlight exposure.