Iodine Intake Estimated by 24 h Urine Collection in the Italian Adult Population: 2008-2012 Survey.

Roberto Iacone,Ornella Russo,Andrea Di Lenarda,Pasquale Strazzullo,Luigi Palmieri,Daniela Galeone,Pietro Formisano,Simona Giampaoli,Chiara Donfrancesco,Paolo Emidio Macchia,Paola Iaccarino Idelson,Cinzia Lo Noce

doi:10.3390/nu13051529

Abstract

Monitoring the population iodine status is essential for iodine deficiency eradication. This study assessed the average dietary iodine intake and the iodine status of a random sample of the Italian general adult population. The study population included 2378 adults aged 35–79 years (1229 men and 1149 women) from all 20 Italian regions, participating in the Osservatorio Epidemiologico Cardiovascolare/Health Examination Survey 2008–2012 (OEC/HES), and were examined for iodine intake in the framework of the MINISAL-GIRCSI Programme. Dietary iodine intake was assessed by the measurement of 24 h urinary iodine excretion. The median daily iodine intake of the whole population was lower (96 µg/d, interquartile range 51–165) than the daily adequate iodine intake according to both EFSA and WHO recommendation (150 µg/d), with a significantly lower value among women (85 µg/d) compared with men (111 µg/d). Iodine intake diminished with age and increased with BMI (body mass index) in male but not in female participants, without achieving the adequate intake in any sex, age, or BMI category. In this random sample of Italian general adult population examined in 2008–2012, iodine intake still remained lower than the recommended values despite the implementation of a strategy of iodoprophylaxis based on salt iodization in 2005. These data represent a valuable reference for future monitoring of iodine status in our country.

Highlights

Iodine is an essential nutrient for mammals at all ages, being required for the synthesis of thyroid hormones, which play a fundamental role for a healthy growth and a normal neurological development in children [1] and for energy-yielding metabolic processes at all ages [2]
The main finding of the work is that, in a random sample of Italian adult population examined between 2008 and 2012, over 70% of the study population had an inadequate iodine intake according to both EFSA adequate intake (AI) definition (150 μg/day) and World Health Organization (WHO) standard for iodine status (100–200 μg/L of urine)
Our study conducted between 2008 and 2012 on a large national sample of adult general population represents an important reference for future monitoring of iodine intake and of the population iodine status in Italy

Summary

Introduction

Iodine is an essential nutrient for mammals at all ages, being required for the synthesis of thyroid hormones, which play a fundamental role for a healthy growth and a normal neurological development in children [1] and for energy-yielding metabolic processes at all ages [2]. Since approximately 92% of the ingested iodine is eliminated in the urines [7,8] and the average 24 h urine volume in adults is 1.5 L or more, WHO/FAO (Food and Agriculture Organization of the United Nations) set the AI for iodine in adults at 150 μg/d [9]. This value was confirmed in 2014 by an ad hoc EFSA panel of experts [8]. It is preferred to dietary assessment, which is felt to be much less accurate [10,11,12]

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