Glucose , for example, absorbed from the intestines, constitutes a major source of body energy. Some of the plasma proteins and fats, or lipids, are also used by the tissues for cell growth and energy. Minerals essential to body function, although present only in trace amounts, are other important elements of the plasma. The calcium ion, for example, is essential to the building of bone, as is phosphorus. Calcium is also essential to the clotting of blood.
Copper is another necessary component of the plasma.