Hypophosphatemia is a common electrolyte disturbance in critically ill patients and can have significant clinical consequences if not properly managed. Phosphate plays a crucial role in cellular energy metabolism, membrane integrity, bone mineralization, and the function of the muscular and nervous systems. Phosphate homeostasis is tightly regulated by hormones such as parathyroid hormone (PTH), fibroblast growth factor 23 (FGF-23), and 1,25-dihydroxyvitamin D. These hormones manage phosphate balance through their actions on the kidneys, intestines, and bones, ensuring adequate phosphate availability for physiological processes.