The body uses sodium to regulate blood pressure and volume. Too much sodium can lead to high bloood pressure. The USDA recommends a daily limit of 2,300 mg of sodium or one teaspoon of salt a day. Eat no more than 1,500 mg of sodium or 2/3 a teaspoon, If you are over the age of 50, African-American. or have a history of high blood pressure, diabetes or chronic kidney disease.