The aim of this book is to increased public awareness of iodine's importance. Iodine is an important inorganic, nonmetallic trace element that is needed in minute amount for the production of thyroid hormone and much other essential biological function.Iodine is important for optimum development of human, including human fertility and reproductive health, brain and intellectual development, and linear growth. Iodine deficiency (ID) is the major cause of endemic thyroid goiter, cretinism, neonatal hypothyroidism, irreversible mental retardation, child and infant death, delayed onset of puberty , menarche , and infertility. About 38% of the world population (2.2 billion) live in areas with ID and are at risk for its complications.Other main aim of this book is to provide sound and up to date Knowledge to foster the international efforts for elimination of iodine deficiency worldwide. Therefore the information is presented in such way to be appreciated by medical professionals as well as whole scientific community and the general population at large.