Hypophosphatemia
Hypophosphatemia is an electrolyte disturbance in which there is an abnormally low level of phosphate in the blood. The condition has many causes, but is most commonly seen when malnourished patients (especially chronic alcoholics) are given large amounts of carbohydrates, which creates a high phosphorus demand by cells, removing phosphate from the blood (refeeding syndrome).
Because a decrease in phosphate in the blood is sometimes associated with an increase in phosphate in the urine, the terms hypophosphatemia and "phosphaturia" are occasionally used interchangeably; however, this is improper since there exist many causes of hypophosphatemia besides overexcretion and phosphaturia, and in fact the most common causes of hypophosphatemia are not associated with phosphaturia.
Common causes of hypophosphatemia
Refeeding syndrome This causes a demand for phosphate in cells due to the action of Hexokinase, an enzyme that attaches phosphate to glucose to begin metabolism of glucose. Also, production of ATP when cells are fed and recharge their energy supplies, requires phosphate.