Vitamin D and Covid-19 | Hacker News Reader

Vitamin D and Covid-19

vitamin-d-covid.shotwell.ca

52 pointsvoisin39 comments

Can we stop posting this until the large randomized controlled trials report back here in another month or so?

Does the body of studies on this page constitute a dearth of evidence?

There actually have been 2-3 RCT so far. This was the most notable.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456194/

Per the linked source, 41 studies including 2 randomized trials show that a vitamin D deficiency increases the severity of COVID-19 infections. Other sources (example: https://www.bmj.com/content/371/bmj.m3872/rr-5) also corroborate the scale of studies indicating a relationship between Vitamin D deficiency and COVID-19 health outcomes.

Some notable findings: one randomized study of 50 people hospitalized for COVID-19 found that of everyone given a high dose of Vitamin D, only one ended up in the ICU (https://www.mayoclinic.org/diseases-conditions/coronavirus/e...). And 80% of those hospitalized for COVID-19 have Vitamin D deficiency (https://www.webmd.com/lung/news/20200518/more-vitamin-d-lowe...). Seroconversion is also higher for those with Vitamin D deficiency (https://www.medrxiv.org/content/10.1101/2020.10.05.20206706v...), meaning that you are also more likely to have caught COVID-19 at some point (in a way that you developed detectable antibodies) with VDD than without.

Interestingly, overall Vitamin D deficiency in the US population is at around 42% (https://pubmed.ncbi.nlm.nih.gov/21310306/), with some minorities having significantly higher prevalence. This might partially explain why the US has worse outcomes for COVID-19 than some other nations, and it may also explain the distribution of which demographic groups are more at risk for COVID-19.

Lastly, the link between VDD and COVID-19 health outcomes also raises a different philosophical question: if those who face adverse health impacts from COVID-19 are at increased risk due to their own poor diet or lifestyle (as indicated by Vitamin D deficiency), should all of society have to shoulder the burden of mask mandates, lockdowns, and other impacts? Or should individuals be allowed to make decisions as to what activities they undertake and what risks they are OK with based on their own assessment of risks and benefits?

Ironic that they then lock-up people in nursing homes in the USA during these lockdowns which prevents them from getting any exposure to the sun.

> This might partially explain why the US has worse outcomes for COVID-19 than some other nations, and it may also explain the distribution of which demographic groups are more at risk for COVID-19.

I think this is true and adds to a list of other things: obesity and cross-reactivity through exposure to viruses (I've been reading ppl suggest that Asia may have exposure to other SARS-like viruses).

To further complicate the web, obesity is itself thought to cause VDD: https://www.livescience.com/26961-obesity-causes-vitamin-d-d...

HN has a strange obsession with this supplement.

That’s because the general consensus is that higher levels of vitamin D are associated with rapid recovery or avoidance of Covid. Rational people would say that’s a good thing and support it.

Is there any sound basis to the “general consensus”?

The "general consensus", that I'm aware of, is the continuous trickle of studies that shows some relation, like those found in this link.

I think a lot of the evidence is marginal. Low vitamin D levels are an indicator of frailty, so all the observational evidence may be showing something other than a causal relationship between vitamin D levels and COVID outcomes.

IV vitamin D seemed to be beneficial in early COVID-19 patients in one randomized trial, which is the best evidence of a causal relationship we have between vitamin D and prevention of severe COVID. Attempts at giving oral vitamin D after diagnosis showed no benefit, but wouldn't really be expected to, either.

There's probably some protective effect, but it's also probably much smaller than most are estimating. That said, taking a small to moderate dose of vitamin D is likely to do more good than harm to people for other reasons, and may provide a small margin of protection against severe COVID. Further, it's cheap and easy to do.

Since March, I've been taking a multivitamin that includes a moderate amount of D.

Did you mean "more good than harm?"

Yah, I edited and fixed on re-read. Pretty stupid for me to be saying the opposite of what I mean. :D

Really eager downvotes on my comment, too, today.

The irony is always lost in these threads criticizing scientific studies by providing vague anonymous opinions.

If you're saying I'm criticizing studies, I've done nothing of the kind. I've attempted to contextualize and summarize the evidence.

Also, I'm not anonymous; my name is on the comment.

Ideally we'd compare it with other promising interventions we hadn't heard of, to avoid availability bias. I'm not saying you shouldn't do it, though.

We're living a global, natural experiment of promising interventions you haven't heard of.

Is this the reason that countries closer to equator are suffering less than those away from it?

Are they? That would be an interesting spatial data plot to see.

There are a ton of confounders there. Most of those countries have younger populations. The outdoor temperature is higher there. They have different economies and population densities.

Or it could be Vitamin D, at least in part. To know the answer somebody has to actually do the science.

Suffering less?

https://www.washingtonpost.com/world/the_americas/coronaviru...

Greece is close to the equator and during November we have had the highest rate of deaths among all EU countries. So I doubt this is the only factor in play.

Older population, no? Study this week showed 90% of the difference among country-level outcomes can be explained by population age distribution.

Greece is around 37ºN, roughly the same as San Francisco. I wouldn't call that equatorial.

I think most of us would. And in fact vitamin D supplementation is associated with all sorts of health benefits having nothing to do with Covid. Take your vitamin D!

That said: the kind of aggregate mortality effect the (comparatively sparse) data on that site points to is absolutely miniscule compared to much more straightforward mitigations like wearing a mask and avoiding restaurants. And these are things that HN is wildly divided on. "Rational people" might wonder why that is.

Are we wildly divided on these things? I've not seen it.

I think wearing a mask is a relatively small benefit but small bends in exponential functions can have massive differences in aggregate outcomes.

I (n=1, but still I browse HN a lot) have only seen posts that are against the idea of wearing masks be heavily downvoted. I've seen a few people discussing whether or not they're important to wear outside, but the WHO seems to agree that being outside makes covid less likely to spread[0], so imho that is a fine thing to discuss

[0] https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/..., under "What makes activities safer?" they list "They are held in outdoor spaces. Indoor spaces with less ventilation where it might be harder to keep people apart are more risky."

If it were the general consensus, this posting (i.e. the summary page) would look different; we'd have much higher powered studies and a clearer view of what was going on.

HN had a strange obsession with masks around March, so this is not necessarily grounds for dismissal.

It does? First time I've seen it mentioned here.

Here's the past year, by date: https://hn.algolia.com/?dateRange=pastYear&page=0&prefix=fal...

Something about it is on the front page every month or two.

Honestly, I'm fine with it. I think more people need to know they should be supplementing with vitamin D. It's possible it doesn't help with COVID-19, but the evidence is enough and the risk of harm low enough that it's clearly a rational decision to supplement at this point.

I don't know that I'd call it a "strange obsession," but it's a popular topic, right up there with intermittent fasting. Here are some active posts just from the last two or three months:

https://news.ycombinator.com/item?id=25289921

https://news.ycombinator.com/item?id=25261441

https://news.ycombinator.com/item?id=25113595

https://news.ycombinator.com/item?id=25077519

https://news.ycombinator.com/item?id=24912172

https://news.ycombinator.com/item?id=24768721

https://news.ycombinator.com/item?id=24734774

https://news.ycombinator.com/item?id=24607645

Three of those are links I posted so maybe it is just my strange obsession!

Like many others have commented, I am baffled why this is not being reported broadly and pushed as part of a low-cost, apparently no downside public health agenda, particularly leading into the darker winter months.

Data needs to be built, but who can say no to a supplement that's relatively cheaply available, in ample supply and doesn't hurt to take reasonable doses over a few weeks?

Clinical trial success is around 14%. Most things fail.

Remember Curcumin?

https://blogs.sciencemag.org/pipeline/archives/2017/01/12/cu...

> Taking the properties and activities all together, though, these efforts would seem to be largely – and almost certainly completely – wastes of time and money. What’s worse, it appears that from 2001 on there are at least 135 registered clinical trials using the stuff. The review goes into four examples for which details are available, all of them complete wipeouts, and those would seem to serve as good proxies for the rest given that no curcumin trial has ever reported any convincing positive results.

Probably because no one here goes outside.

Because it's good for you? Even if it does absolutely nothing to help you defend against COVID-19.

It predates the pandemic. The first studies suggesting "maybe we are all D3 deficient" go back over a decade, and so articles about it have popped up on HN a few times a year. Then add the pandemic and the new implication that it affects COVID outcomes and you start to get a hype cycle.

I will say that I find some value in D3 supplements personally and have used them, at varying levels, since 2009. But like most health issues, its impact can't be reduced down to a one-factor analysis, and often entails discussion of other supplements and deficiencies.

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