He recommends anywhere from 10,000 to 50,000 IU per day which he backs up with studies. N of 1 here but I have a friend who started taking 30,000 IU per day and feels great.
I was tested as having 15ng/ml of vitamin d in my blood. Clearly deficient and I was already taking 1000 IU/day. After a year of 2000 IU/day, it barely improved. I get a decent amount of sunlight outside of work, but I am an office work. Not until I increased to 10000 IU/day did the number materially improve. I've backed it off to 5000 to maintain, but I suspect I should just stay with 10000.
He recommends anywhere from 10,000 to 50,000 IU per day which he backs up with studies. N of 1 here but I have a friend who started taking 30,000 IU per day and feels great.