Readie, A SALT is any Group I metal (Li, Na, K, Rb, Cs) combined with a Group VII Halogen (Halos: salt forming)(F, Cl, Br, I). Thus NaCl sodium chloride is A salt and it is the exact same compound no matter where it is found, as a rock, in the ocean, in the desert, in plants, in animals. Sodium chloride is a naturaly occuring substance and therefore, by FDA regulations is not regulated in any product. Thus the salt content of any food can be naturalally occuring or added during processing, there is no way to distinguish between them.
As far as health is concerned the original medical "salt" studies were flawed. Conversion errors were made in the calculations by a factor of 10. Since no one bothered to "check the math" those flawed studies are quoted over and over.
That being said, Sodium ion plays a large role in all osmotic processes thus helps to regulate body fluids. High sodium ion tissue concentrations reverse osmotic water flow into the tissues producing edema. That extra fluid requires extra pumping power which can add stress to an already stressed cardiovascular system.
Thus sodium chloride is indeed "toxic" (that's why it is able to preserve food) but then so are water, alcohol, Tylenol, Asprin, nicotine, caffine, ricin, and botulinum.
The leathality or LD50 (Lethal Dose 50% of tested population) is surprising:
Water - 90g/Kg (of body mass); Viamin C - 11.9g/Kg; Alcohol 7.1g/Kg; NaCl - 3.0g/Kg; Tylenol - 1.9g/Kg;
Aspirin - 200mg/Kg; Caffine - 192mg/Kg; Nicotine - 50mg/Kg; Ricin - 20mg/Kg; Botulinum toxin - 1 ng/Kg
Note that the Botulism toxin is 10 times more lethal than the Polonium-210 (10ng/Kg) used by the Russians to assassinate Alexander Litvinenko in 2006. Thus 1 gram of botulinum, properly distributed could kill 100,000,000 humans