Iodine content in food: comparison between Azores and continental Portugal

Background and objective(s): Iodine is an essential trace element for the synthesis of thyroid hormones, in particularly for pregnant women and children. Clinical studies in Portugal have demonstrated the existence of a generalized deficiency in iodine of pregnant women and with school-age children particular severity in the archipelago of Azores. The main cause of iodine deficiency is low levels of iodine in foods. A general lack of awareness within the Portuguese population about the importance of iodine in the diet has also been identified. Thus, in this work we address the characterization of iodine in foods available in Azores and continental Portugal to promote the consumption of iodine rich foods. Materials and methods: A total of 110 samples 60 from Azores (Az) and 50 from Portugal (cPT) were analyzed as consumed. The iodine content in dairy products, fruits and vegetables was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results: Analysed foods showed large variation in iodine content, with values of 255μg/l (cPT) and 133μg/l (Az) for milk, 275μg/kg (cPT) and 117μg/kg (Az) for cheese. However vegetables collected in Azores presented higher iodine content than those purchased in continental Portuguese supermarkets. Discussion and conclusion(s): All results are sound supported in metrological tools and aligned with other studies published in the literature. This is a premise to estimate the iodine intake of Azores and Continental population and a contribution to understand the role of this intake in the risk of Iodine Deficiency Disorders observed mainly in Azores region.

This work was supported with co-financing of INSA and World Health Organization (WHO) in the frame of project “WHO Collaborating Centre for Nutrition and Childhood Obesity”.

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