I'm in my armchair thinking autoimmune diseases.
Those who reject this even after reading the following 100% deserve to suffer, but worse yet, they make others suffer, often due to their conflict of interest as shills for pharma. The general commitment to truth is well below zero for those who stand to gain from its suppression.
https://medicalxpress.com/news/2024-10-vitamin-d-deficiency-...
https://medicalxpress.com/news/2022-01-vitamin-d-supplements...
https://medicalxpress.com/news/2018-02-magnesium-vitamin-d-i...
It's worth being aware of that as the recommended limits for vitamin D are laughably too small, so it's common for people to take much larger amounts. I believe that 4k IU is considered a safe adult dosage.