I’m leaning on the expected value rather than robust evidence.
Definitely seems plausible to me that it’s not useful for immune function outside bone health. But priors (it’s the one vitamin not in diet, so everyone is deficient) and the small amount of evidence are enough to make me think it’s net-positive, and even 20% likely to help by a small amount is a relatively large benefit (~ a day of life).
It seems hard enough to find small effect sizes of things via study that I’m not at all surprised meta-analyses showed no evidence for it—and when I don’t really expect to see evidence, defaulting to “do what seems like it would be healthy in the ancestral environment” says sunlight is probably a better bet than supplements, but being non-deficient in vitamin D is probably a better bet than being deficient. (And again, this doesn’t apply to other vitamins because they’re in the diet. It does apply to e.g. sleep and exercise though.)
Scott Alexander says Vitamin D is (TL;DR) just good for bone health, even though studies exist saying otherwise.
https://slatestarcodex.com/2014/01/25/beware-mass-produced-medical-recommendations/
wdyt?
I’m leaning on the expected value rather than robust evidence.
Definitely seems plausible to me that it’s not useful for immune function outside bone health. But priors (it’s the one vitamin not in diet, so everyone is deficient) and the small amount of evidence are enough to make me think it’s net-positive, and even 20% likely to help by a small amount is a relatively large benefit (~ a day of life).
It seems hard enough to find small effect sizes of things via study that I’m not at all surprised meta-analyses showed no evidence for it—and when I don’t really expect to see evidence, defaulting to “do what seems like it would be healthy in the ancestral environment” says sunlight is probably a better bet than supplements, but being non-deficient in vitamin D is probably a better bet than being deficient. (And again, this doesn’t apply to other vitamins because they’re in the diet. It does apply to e.g. sleep and exercise though.)