Good points.
Potassium cyanid and sodium nitrate?
Heheh. Well, as always, examples can be problematic; cyanocobalamin does have a few problems because this form of B12 is purged (nice word for pee) sooner than other forms, due to the cyanide. That's why there are more effective forms like hydroxocobalamin, and, for those with the MTHFR defect, methylcobalamin.

But I'm just fooling around and happen to know a bit about B12 (for all the wrong reasons...).
PS: I once asked for a tapwater test analysis back when I was into keeping koi. The number of scary sounding chemicals and heavy metals on that sheet was enough to give you nightmares. Yet, it was all good news, and the water was perfect for filling/topping up the ponds.
PS2: Maybe if it was called fluffycotton instead of rayon...