I take 6000 Iu of vitamin D3 daily, so I have been having some problems with good sleep for a few days out of the week, but since taking 2000 Iu's right before bed,(4000 during the day) I have been sleeping so much better and good sleep. My 26 year old daughter also started to take her D3 before bed and she also tells me she sleeps better then ever. It is worth trying it, if you are low on your vitamin D3.