I think Vitamin D3 will definitely help your baseline health. I do feel skeptical as to how POIS community, are viewing various POIS symptoms. In my humble view, certain symptoms of POIS dont emerge out of thin air, I think for a vast collection of POIS symptoms, they are pre-existing (and depict the general ill health of POIS community). During POIS, there maybe are some new symptoms (as in my case skin changes), however, I think majority (CNS based specially) they are an exacerbation.