Well, when researching (yet months ago) I remember considering lighting, it's a thought.
But now I'm thinking of trying just Vitamin D by itself (or maybe with magnesium?) I have serum calcium on the high side ranging between 9.8 to 10.4. I'm not sure whether my serum calcium levels are *un*absorbed or what. But if they are unabsorbed, maybe the Vitamin D would help to absorb them. Who knows.