FGF23 excess or hyperactivity causes the waste of urinary phosphate and low levels of 1,25(OH)2D3, thereby leading to HR with characteristic lower limb deformity, growth plate abnormalities, and progressive softening of the bones (osteomalacia), as well as a short stature, muscle and bone pain, weakness, fatigue, joint pain or stiffness, hearing difficulties, enthesopathy, osteoarthritis, and dental abscesses [5]. Here, FGF23 is linked to osteomalacia.