This is stored in the liver and muscles. if there is too little and blood cells burst, too much and they are damaged by crenation

Glycogen is present in the liver and muscles. If glucose is not converted to glycogen and is not disposed off to the liver, then the levels of glucose rises in the blood, causing a hypertonic environment, causing cells to burst.
The low levels of the same causes a hypotonic environment, causing blood cells to shrink, due to outward movement of water.