D5W is unique. It can be categorized as an isotonic solution or a hypotonic solution. The amount of dextrose in the solution makes its tonicity, or solute concentration, similar to that of intravascular fluid, making it isotonic. It also provides free water, following the metabolism of the dextrose. It is also considered a hypotonic solution. D5W is basically a sugar water solution that provides 170 calories per liter but doesn’t provide the electrolyte replacement.