My main suggestion is, if you eat meat, to look into making home-made broth from bones (prefereably free-range/grass-fed). Slow cookers are ideal for this, because what you want is to cook those bones for, like, at least half a day. You get a fuckton of minerals that way, and right now your body isn't just doing stuff with vitamin D, it's also drawing on other resources *handwaves* and part of why you're tired may be because you're running low on other nutrients. Also, seaweed. Like, make rice and stick a piece of kombu in with it and eat the kombu with the rice.

(now I want some rice cooked with toasted sesame oil and kombu but I need to get to bed, like, right now.)