• It is an essential component of the extracellular fluids of the human body.
  • It participates in the transmission of nerve impulses, muscle contraction.
  • It contributes to the regulation of acid-base balance and water-salt balance and it is essential for the function of the nervous system.
  • It contributes to the maintenance of osmotic pressure.
  • It protects the body against excessive fluid loss.
  • It regulates the excitability of muscle and the permeability of cell membranes.