Whenever I take vitamin D it interferes with my sleep. I get weird muscle twitches (hypnic jerks?) like biting down, pulling faces, furiously shaking head as I am semi-conscious about to fall asleep combined with a sensation in my brain that wakes me back up. I know years ago when I tried vitamin D and this happened; when I tried to stop triggered a noticeable increase in my fatigue and I'm not sure if I ever recovered. I can push through and eventually the effect lessens, but it seems unwise when I have no idea why it's happening. Amongst other things I am taking: 25,000iu vitamin A, calcium and magnesium (1000mg/400mg in 3 tablets), and vitamin K2(MK4) 15mg x3. I was thinking of adding strontium too. I have read a few times that some of these should not be taken without vitamin D. I was hoping if anyone could comment if it is unsafe to be taking these without the D? Thanks.