Phosphate - Phosphorus

The test measures the amount of phosphate (PO4) in blood.

Phosphates are needed for energy, muscle and nerve function, and bone formation. Phosphate also plays an important role in maintaining the proper acidity (pH) of the blood.

About 75% of phosphate is present as calcium phosphate in bones and teeth. The rest is in muscles, nerves and as storage in body cells where it is needed for energy. About 1% of phosphate is found in the blood.

Most phosphate in the body comes from food (e.g. beans, nuts, eggs, red meat, chicken and fish). The hormone PTH from the parathyroid gland and vitamin D maintain calcium and phosphate levels by causing the body to take in more/less phosphate from food or excrete more/less phosphate through the kidneys.

Phosphate levels that are too high can result in organ damage because the phosphate can precipitate (crystallize).