When I inexplicably broke my hip about two and a half years ago, the *only* systemic issue they could find (and, trust me, they went full House on me trying to find something,) was low Vitamin D. (Granted, it was late December, and, no, I wasn't spending much time outdoors then.) While that didn't explain the hip at all (because my bone density was good, so it wasn't affecting calcium absorbtion,) it does mean that I've been taking mega-doses of Vitamin D for the past two and a half years (because no one's told me to stop, LOL!) I am keeping my fingers crossed that it has some other, anti-viral effects, too. We'll see.... *remains cautiously optimistic and am not, in any way, tempting the wrath of the whatever from high atop the thing*