The Phosphorus Urine test is a key part of your body's metabolic puzzle. It measures the amount of phosphorus your kidneys are excreting. Phosphorus works closely with calcium and vitamin D for bone health. This test is essential for investigating the cause of recurrent kidney stones and for diagnosing and managing parathyroid gland disorders. It often requires a 24-hour collection. This test is critical for understanding your body's complex mineral balance and creating a plan to prevent future kidney stones.