> Doctors are in fact notoriously bad when it comes to vitamin D.

Most doctors know nothing about the endocrine system, at all. I self taught myself through "Endocrinology: Adult and Pediatric" and I probably know more than 99% of general practitioners out there. Heck, most doctors are likely unaware of the endocrinological functions of D3.

On Endocrinology: Adult and Pediatric, I consider it a must read for anyone btw