Sodium is an important part of your body’s function. Sodium and potassium are what make your muscles contract and relax, not just skeletal muscle (the stuff that makes you move and walk), but also smooth muscle like the muscle that is in your intestines and esophagus but maybe most importantly your cardiac muscle. You can have cardiac issues without the proper amount of sodium and potassium in your diet. And since we’re on such a restricted diet right now you’re probably not getting enough sodium in your diet so it must be supplemented.