The iodized salt has a lot of chemical additives, like iodine and anti-caking agents. One sign of the iodized salt being bad is that it can't be used in pickling for it would make the vegetable rotten.
So let us thing the other way: we should aviod the iodized salt. Except that, you can have a lot of choices free of chemical additives, for example, sea salt, kosher salt, etc. That's the reason it is not a must to use pink salt.
But, according to Ayurveda which is the traditional Indian medicine, the rock salt is the best salt, and the pink salt is a kind of it.
