How much Vitamin D should I take?

Consultant Physician, medical researcher and author, Dr David Grimes conducted much original research on the essential to life Vitamin D. Buy his inexpensive latest book here. 2 minor corrections - 150nmol/L = 60ng/mL (not 80ng/mL as stated and at 2min 27secs) 57min 11 secs Calcifidiol appears in the BNF here: and medicinal form here