Sodium is a very valuable component of your daily diet. Everyday, you have to take in not less than 1,500 milligrams and no more than 2,300 milligrams of this compound. It is a valuable component in maintaining blood pressure. Sodium retains water in your blood. If you have too much additional water in your blood vessels, then your blood pressure will surely elevate. It also retains water in your tissues. This is why you gain weight when thereâ€™s too much sodium in your diet.