Comment by TacticalCoder | Hacker News Reader

Comment by TacticalCoder | Hacker News Reader

Here's another take on the subject:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9258852/

"supplementation was associated with a significant lower risk of both Covid-19 severe disease (SRR 0.38, 95% CI 0.20–0.72, 6 studies) and mortality (SRR 0.35, 95% CI 0.17–0.70, 8 studies)"

Note that in "part 3" devaboone says Vit D failed to live up to its expectation and she posts a graph showing that Vit D only works to counter Vit D deficiency.

Since then a study came out, studying 200 000+ individuals (which is 10x more than the biggest study in the studies she cherry picked in her part 3 if I'm not mistaken), showing that Vit D supplementation did (and does) help combat the worst disease the world has known in decades (if not centuries).

Time to update the studies used in her "part 3" to conclude that Vit D supplementation only helps fixing Vit D deficiency?

For my casual reading of that study I linked to is this: those who told people to start taking Vit D supplementation during Covid did actually save lives and did actually help many have less severe symptoms.

I do think that that ship has sailed: we now know Vit D supplementation does work.

We can nitpick on whether 1000 IU or 2000 IU per day is too much or not but I don't think that saying that "Vit D supplementation only works at fixing Vit D deficiency" is a serious take anymore (once again: Part 3 clearly shows a graph saying just that).

I think doing an update would be great, when I have time. Just a note: the article you cited was not a randomized controlled trial. It is a meta-analysis that included only 2 small RCTs and a ton of observational studies.

The image from my post that you are referring to is looking only at RCTs. In RCTs, Vitamin D supplementation rarely shows a positive effect. This does not mean that Vitamin D supplementation is useless.

Even in my post from 2020, I mention that respiratory illness is one area that has shown a benefit of Vitamin D. Here is what I wrote:

"The areas in which meta-analyses have identified benefits from Vitamin D:

Fracture prevention in elderly nursing home residents (when also given with calcium): This is not surprising. We know that Vitamin D and calcium can prevent bone loss in severe Vitamin D deficiency. Elderly adults who are not getting outside are more likely to be severely deficient in Vitamin D, and supplements likely help.

Asthma and respiratory infection: Vitamin D seems to reduce asthma attacks in adults with mild to moderate disease, and daily or weekly Vitamin D seems to prevent acute respiratory infection in those with Vitamin D less than 10 ng/ml (25 nmol/l). There is considerable excitement around Vitamin D's potential role in Covid treatment, though we do not yet have enough evidence to make a definitive conclusion.

Cancer mortality: Vitamin D does not appear to prevent cancer, but may reduce death rates from cancer overall (when all cancers are combined) when Vitamin D is taken for several years. It is not known whether Vitamin D itself fights cancer. It could also be that individuals with cancer are more prone to developing severe Vitamin D deficiency, which leads to bone loss, fragility, and fractures, which increase mortality.

Atopic dermatitis (eczema): Vitamin D supplementation may prevent exacerbation of eczema. There are only a small number of trials, with small numbers of patients, so this requires more research."

We do have more information on Covid and Vitamin D now, and I would agree that Vitamin D was likely beneficial for some people. I would also add that I had a bunch of patients come in with high calcium because they started high-dose Vitamin D during Covid and never decreased the dose.

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