Serum Phosphorus Level Test - Serum Phosphorus Test

This laboratory test measures the concentration of inorganic phosphorus (in the form of phosphate, HPO₄²⁻) in blood serum. Phosphorus plays a vital role, along with calcium, in the formation of hydroxyapatite, the main mineral component of bones and teeth. It is also an essential component of energy-producing ATP molecules, DNA, and cell membranes. Its blood level is very tightly regulated by the kidneys, parathyroid hormone (PTH), and vitamin D.