Update on iodine status worldwide.
OBJECTIVE
Salt iodization has been introduced in many countries to control iodine deficiency. The two most commonly used approaches to assessing iodine nutrition on the population level are estimation of the household penetration of adequately iodized salt (HHIS) and measurement of urinary iodine concentrations (UICs). The aim of this review is to assess global and regional iodine status in 2012 by using each of these indicators.


RESULTS
The most recent national data on HHIS were obtained from UNICEF. The most recent data on UICs, primarily national data in school-age children, were obtained from a systematic literature search, the International Council for the Control of Iodine Deficiency Disorders and the WHO Micronutrients Database. The median UIC was used to classify national iodine status and the UIC distribution to estimate the number of individuals with low iodine intakes. Thirty-two countries are iodine deficient based on the national median UIC. Globally, 29.8% of school-age children (246 million) are estimated to have insufficient iodine intake. Out of 128 countries with HHIS data, 37 countries have salt iodization coverage that meets the international goal of at least 90% of households consuming adequately iodized salt and 39 countries have coverage rates of less than 50%. Overall, ≈70% of households worldwide have access to iodized salt.


CONCLUSIONS
Iodized salt programs need to be strengthened and extended to reach nearly one-third of the global population that still has inadequate iodine intakes.
Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Switzerland. michael.zimmermann@hest.ethz.ch
Michael B
MB
Zimmermann
Maria
M
Andersson
D002648:Child; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005260:Female; D014943:Global Health; D006801:Humans; D007455:Iodine / Q000008:administration & dosage / Q000172:deficiency* / Q000652:urine; D008297:Male; D009313:National Health Programs; D015596:Nutrition Assessment; D009752:Nutritional Status; D011159:Population Surveillance; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*
D017673:Sodium Chloride, Dietary; C034024:iodized salt; D007455:Iodine