I fear that the second this hits major mainstream media, all vitamin D capsules still left in stores will immediately be hoarded by the same people who hoard toilet paper...
It already is here in The Netherlands. Vit-D and Vit-D supplements are pretty much all gone.
Luckily we have a large supply in house thanks to being forgetful and needing it for the baby. My wife has a large supply of girly multivits and I managed to score a months supply of multivits.