I can vouch for the efficacy of vit D3 . It really works.
Until a month ago I could get no sleep without sleeping pills. Then I read somewhere about magnesium and D3 helping sleep and for the last month or so, sleep has come easily and restfully. Even though pain wakes me I just drift off again.
It may well be the grandchildren who have had little sun this year and who seem to have very little sleep could also be in need of D3.
I am constantly amazed at the wealth of info that you kind folk share here.