Here’s how you can tell if you are Vit D “deficient “, look at your teeth , do they have a yellow cast to them . You can brush your teeth all you want it’s useless, as I stated in my DYK section . Nothing can stain your teeth , their not dirty , it’s a yellow cast in the teeth from being low in D.
Here’s why your teeth look yellow , when you don’t get enough calcium [whole dairy] your skeletal system [ the larger bone structure] say’s to the smaller bone structure [teeth] ” were way bigger so we need way more calcium” and “leeches” the calcium from your teeth . That’s why your teeth look yellow, it has nothing to do with brushing your teeth .