Sorry I don't have an answer to your question about "salts". But I have something else that you might be interested in. Maybe someday you could do some research on this:
You said you have been looking into "natural and organic foods". I read in, "Doctor Gundry's Diet Evolution", that some (maybe most?) plants have the ability to produce some toxins to keep bugs away. Okay, most people probably know that, but there's more. Some (or perhaps many?) vegetables can actually produce more toxins in response to being nibbled on by bugs.
So here's the point: If pesticides are used properly, there will be no bugs and no nibbling. So veggies will not increase their natural toxins; although, you may get a small residue of pesticides in your diet. On the other hand, if veggies are organically grown and there's some nibbling by bugs, you may get more toxins from that than you would from the commercially grown veggies.
What do you think? Would that be an interesting class project to find out more about what impact that might have on one's diet?