Sodium occurs naturally in most foods. The most common form of sodium is sodium chloride, which is table salt. Milk, beets, and celery also naturally contain sodium. Drinking water, also contains sodium, but the amount depends on the source.
Sodium is also added to many food products. Some of these added forms are monosodium glutamate (MSG), sodium nitrite, sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate. These are in items such as Worcestershire sauce, soy sauce, onion salt, garlic salt, and bouillon cubes.
Processed meats like bacon, sausage, and ham, and canned soups and vegetables also contain added sodium. Fast foods are generally very high in sodium.