Earlier iodine deficiency disorder was restricted to endemic goiter belt of Himalaya region, but it has been found recently that it is a persistent problem in several other regions of the world. Out of total 183 countries, it is found that in 118 counties, IDD has been a public health concern and 51 countries are blessed without IDD.
As per the national IDD survey carried out in 40 districts all over India by NNMB in 2003, the prevalence of total goiter ranges between 7.2 to 39.6%. Higher prevalence is seen in most eastern Indian states and some of the northern states. Nearly 197 districts all over India were found to be endemic for IDD.