World Status of Monitoring of Iodine Deficiency Disorders Control Programs

Monitoring and evaluation are the last phases of a national iodine deficiency disorders (IDD) control program but among the most important. This paper summarizes the latest recommendations by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), and the International Council for Control of Iodine Deficiency Disorders (ICCIDD) about indicators and their normative values for monitoring the progress of IDD elimination and illustrates the successful monitoring programs in Switzerland and in China. Salt is the usual vehicle for iodine supplementation and quality control for iodine content can be assessed quantitatively by titration and qualitatively by simple test kits that can be used in the field. The most useful indicator of iodine nutrition is the median urinary iodine concentration. Thyroid size, especially by ultrasound, and neonatal thyrotropin (TSH) are also valuable. In Switzerland, access to iodized salt on a voluntary basis started in 1922. The initial level of iodization...