>>76501136
>Vitamin D deficiency causes hairloss
I have always suspected there's some truth to this but...

>Look at surfers
most famous surfer of all time went bald

>homeless bums
I remember hearing that schizophrenia is positively correlated with good hair genes

Somewhere along the everlasting mystery of baldness, humans living indoors has to be in there. Hair protects our scalps from sunlight, after all. But I'm not really confident that it's as major as you suggest.