INTRODUCTION Iodine deficiency is one of the most common preventable causes of mental retardation in the world today (1). Iodine deficiency disorders (IDD) are a major publichealth problem in India. An estimated 167 million people in India are at risk of IDD, of whom 54 million have goitre, and over 8 million have neurologic handicaps (2). Of 457 districts in the country, 275 have been surveyed for IDD, and 235 have been found to be endemic. These districts cover all the states and Union Territories of India (3).
