Review of Iodine and Salt Sources for Establishing Iodization Standards

Abstract

Objectives: The ICCIDD/GN Iodine Task Force was established in response to changing environment and program maturity of salt iodization programs worldwide. It aims to improve the evidence and thus the quality and effectiveness of iodine nutrition programs to help update program guidelines. To review dietary sources of iodine intake, including salt from different sources and other natural iodine sources to inform the development of iodization standards. Methods: A review of published literature and reports, data and/or information from national programs for eliminating iodine deficiency disorders was conducted to gather both knowledge and program experience. Results: Globally salt intake through processed foods is increasing; however, in many countries such salt is not iodized. Except for marine food, most natural food sources are low in iodine. In Western countries without mandatory Universal salt iodization, the most significant food groups contributing to iodine intake are dairy and cereal products, however, there is a large disparity in iodine content within and between foods due to natural variations. Little information exists regarding the additional dietary iodine via iodized livestock salt. Generally, iodine content in drinking water is low and contributes relatively little towards iodine intake of large populations. Conclusions: Natural sources of iodine in the diet as well as the iodine contribution via livestock salt as less informative for establishing national standards however, a key consideration  is the source of dietary salt. Since most of the salt intake proceeds from industrial salt, iodine standards should be applicable to the total dietary salt supply.