Phosphorus is one of the minerals that are present in our body and is responsible for building and repairing bones and teeth, helping nerves function, and making muscles contract. About 85% of the phosphorus is contained in our bones, and it is controlled in our body by our kidneys. The phosphorus urine test is used to check the amount of phosphate present in our body. It is done because both the high level and low level of phosphorus can be dangerous for our health. These conditions can be the indication of some serious diseases.