Sodium, an essential mineral, is found in the table salt. 
It is involved in nearly every body function, including 
water balance and muscle contraction. 

Some people experience high blood pressure when they eat lots of salt.
They are called "salt sensitive." Although the relation a high-salt 
diet to the onset of high blood pressure has remained a very 
controversial issue, there is no question that once hypertension 
develops, sodium has to be limited.

Hypertension also has been found associated with low intake of 
calcium, magnesium, and potassium.

Most animal foods have a high content of natural sodium. 
Biscuits and pancakes, soy sauce, catsup, commercially prepared or 
canned soups and vegetables, ham, sausages, bacon, hot dogs, 
smoked meat or fish, frozen and fast foods are high in sodium.
Estimated minimum for sodium: 500 mg /day
Recommended maximum intake of salt: 6 g/day (2400 mg sodium)