Phosphate is an essential building block of life. It is one of the most abundant minerals in the human body and has vital roles in both structure and function thereof. Broadly, through a macroscopic lens, phosphate is important for mineralization of the skeleton. On the other hand, at the cellular level, phosphate is an essential component of cell membrane phospholipids and is vital for nucleotide and protein synthesis. Functionally, phosphate is the elementary unit of ATP, the cellular energy currency, and has a central role in energy metabolism. It also contributes majorly to cellular signalling and metabolic cascades by modulating protein function through phosphorylation and dephosphorylation reactions. It is an important physiological buffer for acid-base regulation in blood and urine. The physiology of phosphate balance and regulation is vital to understanding these disorders of phosphaturia and has been covered in details in other chapters [1*], [2].