Vitamin D deficiency is linked to teeth grinding and is correlated to sleep apnea patients. It might be worth it to take a 5000 IU pill along with sunshine walks close to solar noon to see if it improves your situation.
I use dminder to track my estimated vitamin d levels.
I did this pretty regularly and when a routine blood test showed my serum vitamin D at the top of the range, I was told to lay off the daily 5000 IU vitamin D, there is indeed such a thing as too much.
No impact anybody could measure or otherwise determine for me at the time, but if you keep going and it does get too high you get too much calcium in various places which can cause a series of problems.
I use dminder to track my estimated vitamin d levels.