An interesting note, my son have routine bloodwork for his epilepsy meds, and for a while his calcium was so high. Turns out the culprit was he was taking too much vitamin D. When he stopped, his calcium numbers dropped to normal.
I really with more GPs would do lab tests for nutrient deficiencies. Functional docs will but they are crazy expensive, out of network, and the supplements they recommend are expensive and didn’t work for me either.
I spent nearly $2k on a funtional doc once who basically came up with the dx that I was severely anemic but by the time I found out I had already had to have a transfusion at the hospital 🙄
The same thing applies to D as it does calcium; BOTH need magnesium (in high enough doses of a quality form) in order to absorb. If you do a bit a research you’ll also see that there’s decent info on epilepsy being caused by low mag.