Iodine Deficiency

Abstract

Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected. However, about 50% of Europe remains mildly iodine deficient, and iodine intakes in other industrialized countries, including the United States and Australia, have fallen in recent years. Iodine deficiency during pregnancy and infancy may impair growth and neurodevelopment of the offspring and increase infant mortality. Deficiency during childhood reduces somatic growth and cognitive and motor function. Assessment methods include urinary iodine concentration, goiter, newborn TSH, and blood thyroglobulin. But assessment of iodine status in pregnancy is difficult, and it remains unclear whether iodine intakes are sufficient in this group, leading to calls for iodine supplementation during pregnancy in several industrialized countries. In most countries, the best strategy to control iodine deficiency in populations is carefully monitored universal salt iodization, one of the most cost-effective ways to contribute to economic and social development. Achieving optimal iodine intakes from iodized salt (in the range of 150-250 microg/d for adults) may minimize the amount of thyroid dysfunction in populations. Ensuring adequate iodine status during parenteral nutrition has become important, particularly in preterm infants, as the use of povidone-iodine disinfectants has declined. Introduction of iodized salt to regions of chronic iodine deficiency may transiently increase the incidence of thyroid disorders, but overall, the relatively small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency.

Thyroid volume in Swedish school children: a national, stratified, population-based survey

“…The first national evaluation of iodine status in Sweden was performed according to the recommendations of the World Health Organization (WHO) (World Health Organization, 2007;Zimmermann, 2009) and the results have been presented (Andersson et al, 2009). Urinary iodine concentration (UIC) was measured in a representative national sample of children aged 6-12 years: the national median UIC is 125 mg/l, indicating optimal iodine nutrition.…”

Thyroglobulin as a Biomarker of Iodine Deficiency: A Review

“…odine is needed by the thyroid gland to produce thyroid hormones required for normal growth and development (1). Insufficient iodine intake causes iodine deficiency, which affects millions of people worldwide (2).…”

Iodine Deficiency in Pregnant Women Pre- and Post-Mandatory Iodine Fortification in Australia - An Epidemiological Review

“…Except in breastfeeding women, urinary iodine excretion accurately reflects recent iodine intake, with about 90% of dietary iodine appearing in the urine [14]. Although not a sufficient measure for individual iodine status, MUIC can be used to validly assess the population status [15].…”