Studies using specific and sensitive techniques, to assess the functional status of thyroid in areas with iodine deficiency and endemic goitre, show large scale prevalence of functional failure among neonates, children and adults. As thyroxine deficiency can impair quality of human resource, poverty and socio-economic backwardness in endemic areas may have a causal nexus with nutritional iodine deficiency. Eradication of NID, therefore, is an essential first step in the socio-economic transformation, through human resource development, of goitre endemias in developing countries.