The Yin and Yang of Iodine in Human Physiology

Abstract

To prevent iodine deficiency disorders (IDDs), the universal salt iodization (USI) programme has been initiated in many such regions, including several environmentally iodine-sufficient regions ignoring iodine status; as a consequence, thyroid dysfunctions, namely hyperthyroidism, hypothyroidism, autoimmune thyroid diseases, endemic goiter and even thyroid cancer including infertility, stillbirths, abortions, and embryotoxicity are found common among the excess iodine-induced population. In other words, the consequences of iodine deficiency and excess are almost ‘U’- shaped. Chronic intake of low iodine affects the overall physiological functions of humans; however, such effects are also observed when excess iodine is consumed. This article will provide novel information regarding the deficiency and excess of iodine or, in other words, The Yin and Yang of Iodine in human physiology.