Iodine is an essential building block for the synthesis of the thyroid hormones T3 and T4. The key is to provide sufficient iodine daily for optimal thyroid function, not too little or too much. This balance is central to Dr. Pieter Jooste’s talk on meeting global iodine requirements. Beginning with the role of iodine in the pituitary-thyroid axis, Jooste explains how deficiency or excess of this essential mineral affects humans at all stages of the life cycle, from fetal development to adulthood. Thus, the strategies for meeting iodine requirements can be divided into those addressing deficiency, and those addressing excess iodine.
Joost compares and contrasts the strategies used by different countries to encourage iodine intake or to minimize excess dietary iodine. How can we walk the line between not enough and too much? Regulating the processing of food may be one answer. Salt intake, which comes primarily from processed foods, is a major source of iodine, and this should be tailored to meet the specific needs of the target population. Joost urges policy makers and nutritionists to think globally but to act locally when designing strategies to meet iodine requirements.