The human body needs only a small amount of salt (sodium). It is used to regulate body fluids and muscle contractions and to help pass on nerve impulses. Only about 200 milligrams of sodium is needed for the body to work. This is the amount of sodium in about 1/10 teaspoon of salt! Most of the time, we consume much more than this.
Walters, Jackie, "Empty Calories: Know the Limits on Salt (Sodium)" (2012). Family and Consumer Sciences Publications. 39.