Iodine deficiency disorders: contemporary scientific issues.

Iodine deficiency is the leading cause of preventable intellectual impairment and is associated with a spectrum of neurologic and developmental pathology. More than one billion people are at risk. The developing fetus, newborn, and young child are the most susceptible to the effects of an iodine-deficient diet. If intervention is not initiated in a timely fashion, the pathophysiologic abnormalities become resistant to treatment and permanent intellectual, neurologic, and somatic deficits result. The technology of iodine deficiency intervention is well established. Iodized salt, the preferred method, is easy to produce, administer in physiologic doses, and is cost effective. The distribution of iodized salt and social marketing are key to a successful iodine deficiency elimination program. In remote regions, iodized oil is a useful interim intervention. However, it is clear that technology is not enough. Any national effort to eliminate iodine deficiency must extend far beyond the Ministry of Health. The program will require the full participation of a range of national government ministries and agencies and the full support and participation of local or regional governments.