A Phosphorus blood test measures the level of phosphate in the blood. Phosphorus is an essential mineral found in the bones, teeth, and cells of the body. It works closely with calcium and vitamin D to build strong bones and teeth, and plays a key role in energy production, cell membrane structure, kidney function, muscle contraction, and nerve signaling.
This test is used to evaluate phosphorus levels in patients with kidney disease, bone disorders, or conditions affecting calcium and phosphorus balance. Abnormal phosphorus levels can indicate kidney disease (most common cause of elevated phosphorus), hypoparathyroidism or hyperparathyroidism, vitamin D deficiency, malnutrition, or alcoholism. It is often ordered alongside a calcium test and kidney function tests as part of a metabolic panel.
