Reply To: So, my Vitamin D levels have been low, 23. I tried supplementing with 1000 IU per my doctor's request the last five days. I initially felt a little better in mood and energy. But, by the fourth day my sleep started getting really weird. Constant disruptions, vivid dreaming. I was taking 1000 IU early morning around 8:00 am. I am exhausted. Has anyone experienced this or similar reactions to Vitamin D?