The D3 I recommend is spring vally brand from Walmart.
I started out with 4ooo micrograms at night an hour before bedtime. I pulled back to 2000 mcg's because the Iodine
increase that I implemented on myself magnyfied D3's effect. You may only need 1000 mcg. 2000 mcg's causes me to sleep very deeply and my Dreams are so real it is almost scary. But I wake up very very refreshed.