Comment by jonex | Hacker News Reader

Comment by jonex | Hacker News Reader

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Great that you feel better! There are several potential explanations for this, for example: * It could be pure chance and selection bias, for you it seems unlikely, but consider how many took the same advice and saw not effect, they wouldn't post about it. This is why we need larger sample sizes and a control group to compare to. * It could be placebo, maybe your expectations made you notice and appreciate the happiness, maybe also strengthening it. This is why we need to make studies blind by using a placebo group. * There was indeed an effect because you were vitamin D deficient.

Recently a large study was published where they gave a large group vit D to look for depression incidence and they could not find any effect. There's a lot of parameters that could affects the results so it doesn't mean there is none, but probably that it's not as simple as "give everyone vit D and we get rid of depression".

Oh for sure, placebo is a strong possibility for me (the sense of taking action perhaps provides the mood improvement which is not quite placebo but a related effect); also on HN we're perhaps a lot more likely to be "shut-ins" (or approaching that) and so we're starting from a non-representative pool.

For me, I just noticed a few comments saying it helped their depression, was considering VitD already for Covid19 reasons, and figured the possible level of harm was almost zero so I'd give it a shot.

Not sure I'd expect a large randomised group to have a noticeable effect (can you link the study you mention, please) but perhaps "people who have reported depression, have been tested and found to be low in VitD" as a starting group and then see if it does better than placebo.

Thanks for your comment.

For people with vitamin D deficiency I would not be surprised if there's a connection to depression and I guess standard advice applies: If you think you might be at risk, get yourself tested. If nothing else, you can avoid experiencing the bone related issues that a vit D deficiency might cause.

This was the study I was thinking of (they did not target people with depression) https://jamanetwork.com/journals/jama/article-abstract/27689...

Weirdly I couldn't find any studies on the effects of supplementing with vitamin D for depression, even though there's plenty of studies on the correlation, and even one study where they used it for treatment, without any control group...

Thanks, appreciate your useful response.

I guess the lack of studies comes down to the morality of in vivo testing of treatments; the chances of someone untreated going off the rails is considered too great a risk.

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