I think you missed my point. vitamin D levels in and of themselves aren’t an affliction. The “correct” level is established by looking at what everyone else has and also by trying to look for comorbidities. But the comorbidities are often hard to tease out; about the only disease we know is rickets. Everything else is weakly correlational for vitamin D.
How do you think they define healthy levels of other hormones like testosterone and estrogen? They look at the range of levels for them, they look to see when they think diseases start, and they say those are correlated and you should adjust.
>Everything else is weakly correlational for vitamin D.
All cause mortality is correlational for vitamin D.
Various disease outbreaks (common cold, etc) and severity are correlational for vitamin D.
etc
We even know by which mechanisms so it's not like this is far fetched stuff where we're overlooking things.
This kind of stuff slaps you in the face if you live in the northern half of europe.
To then think us now spending the majority of our waking hours indoors and the prevalence of those things and seasonal depression in winter when one leaves in the dark and comes home in the dark all has no effect....I think that's just hubris.
Similarly, many things have issues that may not seem like issues at first. For instance most people are deficient in protein owing to simply not getting enough and a significant chunk of what they do get coming from sources with extremely low digestibility/DIAAS scores.
And somebody may not even realize this until they decide to start downing a few more chicken breasts per day and suddenly see their energy levels skyrocket, their hunger diminish, and so on. But if you surveyed them prior, they'd claim to feel perfectly normal.
Another one is testosterone which is extremely unfortunate because there's no remotely natural way to meaningfully regain significant amounts of it, but TRT is a life changing thing for many people who have low testosterone which in modern times is a huge chunk of all men and essentially all of them over a certain age.
Many things about our society are extremely new compared to the conditions for which our bodies are evolved to be in.