Most of it is in cells controlled by hormones. Rest of body water is in plasma, mucous, bones, and fluid in eyes (among other places) Comes from 3 places: what we drink, water in food we eat, breakdown of food in body. Loss most water is lost through our skin through sweat. Thirst is an adequate guide in healthy adults, not for. There is no dietary recommendation for water. Salt intake is mostly from food processing (it"s a preservative), then salting food, the natural salt in food. Foods high in sodium are typically low in sodium. Too much and too little will harm your heart. Potatoes have more than bananas and oranges. Beans and milk are also good sources. 2 major functions: bone structure, calcium bank. 1 cup of milk = 300 mg calcium. Most adults need 1000 to 1200 mg/day. Blood level is maintained at the price of bone calcium. Blood level can be maintained despite inadequate calcium intake.