Review questions Chapter 12 1 What are the functions of water in the body Water in body fluids carries nutrients and waste products throughout the body maintains the structure of large molecules such as proteins and glycogen participates in metabolic reactions serves as the solvent for minerals vitamins amino acids glucose and many other small molecules so that they can participate in metabolic activities acts as a lubricant and cushion around joints and inside the eyes the spinal cord and in pregnancy the amniotic sac surrounding the fetus in the womb aids in the regulation of normal body temperature as the evaporation of sweat from the skin removes excess heat from the body and maintains blood volume 2 What are dietary sources of water Dietary sources of water include water itself other beverages and nearly all foods Most fruits and vegetables contain up to 90 and many meats and cheeses contain at least 50 Also metabolic water is generated as an end product during condensation reactions and the oxidation of energy yielding nutrients The kidneys excrete obligatory water enough water to carry away the waste products generated by a day s metabolic activities a minimum of about 500 mL or 2 cups per day plus additional water as needed to balance intake in the urine In addition to urine water is lost from the lungs as vapor and from the skin as sweat some is also lost in feces 3 How is water lost in the body Kidneys urine Skin sweat Lungs breath GI tract feces 4 What is the difference between major and trace minerals Major minerals are those essential mineral nutrients that the human body requires in relatively large amounts greater than 100 milligrams per day whereas trace minerals are those that the human body requires in relatively small amounts less than 100 milligrams per day The distinction between the major and trace minerals does not mean that one group is more important than the other all minerals are vital The major minerals are simply present and needed in larger amounts in the body 5 How do vitamins and minerals differ Unlike the organic vitamins which are easily destroyed minerals are inorganic elements that always retain their chemical identity The minerals also differ from the vitamins in the amounts the body can absorb and in the extent to which they must be specially handled Some minerals such as potassium are easily absorbed into the blood transported freely and readily excreted by the kidneys much like the water soluble vitamins Other minerals such as calcium are more like fat soluble vitamins in that they must have carriers to be absorbed and transported And like some of the fat soluble vitamins minerals taken in excess can be toxic 6 What is the major contributor to sodium in US diets Processed foods 75 of sodium in the diet comes from these kinds of food 7 What are some food sources of calcium Milk milk products Fortified foods Tofu Broccoli Sardines Almonds 8 What are consequences of low calcium intake in childhood Peak bone mass is achieved by late 20 s and all adults will lose bone mass starting between 30 and 40 years of age Consuming adequate calcium in childhood is important for achieving peak bone mass and reducing one s risk of osteoporosis later in life 9 How is osteoporosis diagnosed DEXA scan There are no blood tests to diagnosis it