What are the Causes of Hyperphosphatemia?

Hyperphosphatemia is a condition in which the levels of the phosphate ion become abnormally high in the blood. Phosphate is an important ingredient in all cells and the bones, and it also acts as a buffer in the blood to keep the acidity of the blood from changing. Hyperphosphatemia can often result in the phosphate combining with calcium to form little deposits in many tissues. The best treatment of hyperphosphatemia is the administration of drugs which will bind to the phosphate and help expel it from the body.

Intake

• Although a rare cause of hyperphosphatemia, excessive intake of phosphate can cause hyperphosphatemia. Foods that are high in phosphate are soda, chocolate, biscuits (from the supermarket), ketchup, frozen pizza and hot dogs. Massive intake of these foods can result in hyperphosphatemia, especially if kidney function is not ideal.

Vitamin D

• One function of vitamin D is to help absorption of phosphate by the gastrointestinal system and then secretion by the kidneys. As a result, large amounts of vitamin D could cause hyperphosphatemia if phosphate builds up in the gastrointestinal system. In general, these levels of vitamin D intake can only occur by taking too many vitamin supplements, as there are no foods with enough vitamin D to easily cause vitamin D intoxication.

Kidney Failure

• One of the main roles that the kidneys have is processing and excreting waste through the production of urine. When the kidneys fail, the compounds that the kidneys normally excrete, such as phosphate, begin to build up in the bloodstream. This condition can eventually lead to hyperphosphatemia.

Hypoparathyroidism

• The parathyroid is a gland that is located very near the thyroid gland, and it is responsible for secreting the parathyroid hormone. If the parathyroid becomes damaged via trauma or an autoimmune disease, decreased parathyroid hormone will result. One of the functions of parathyroid hormone is to make the kidney secrete phosphate, so hypoparathyroidism can lead to hyperphosphatemia.

Cell Lysis

• Cells contain large amounts of phosphate. When a large number of cells die suddenly and are broken down, this releases the phosphate into the bloodstream. Some conditions that can cause this massive release of phosphate are rhabdomyolysis (where muscle cells are suddenly broken down) and tumor lysis syndrome (a result of killing tumors with radiation and chemotherapy). This can also lead to hyperphosphatemia.