I take 5000mg per day based on the recommendation of my neurosurgeon for treatment of my cavernoma, a veinous malformation in my brain that can bleed. He is the #1 in the world for research in my condition and stands by the assertion that his patients who take D3 fare much better than who do not. I haven’t had another bleed under his care and he has provided valuable other neurological advice for another condition as a second opinion so I take his advice very seriously, unlike some other “doctors.”