If sodium is a concern to you, your water quality improvement professional can explain the amount in softened water.
This varies, depending on the hardness of the water supply. Any person on a sodium-restricted diet should follow the advice of their physician. All municipal water supplies contain some naturally occurring sodium. If the diet is very strict, discuss the use of RO, or some other water quality improvement system to reduce the amount to meet your requirements.
For the sake of comparison, one slice of white bread contains about 114 mg. An eight-ounce glass of milk contains 120 mg. If your water contains 10 grain per gallon (GPG), and if you consumed a total of one quart of softened water a day, your additional intake would be 75 mg. That is less than either a slice of bread or a glass of milk.