Iodine Status among Somali Immigrants in Norway.

Ahmed Madar,Espen Heen,Haakon Meyer,Helle Meltzer

doi:10.3390/nu10030305

Abstract

We lack knowledge about iodine status in the Norwegian population in general, and particularly among immigrants. We aimed to estimate the iodine status and potentially associated factors in a Somali population in Norway. Somali men and women aged 20–73, who were living in one district in Oslo, were recruited between December 2015 and October 2016. Twenty-four-hour urine was collected from 169 participants (91 females and 78 males). Iodine was analysed using the Sandell–Kolthoff reaction on microplates and colorimetric measurement. Information about diet was collected using a short food frequency questionnaire. Iodine intake was calculated from the 24-h iodine excretion. The mean urine volume over 24-h was 1.93 liters (min–max: 0.55–4.0) and the urinary iodine concentration (UIC) varied from 13 to 263 µg/L with a median value of 62.5 µg/L indicating a population with mild iodine deficiency. The median daily iodine intake for the study population was estimated to be 124 μg/day. Mean serum thyroid-stimulating hormone, thyroxine (T4) and triiodothyronine (T3) was 2.1 (SD 1.1) mU/L, 15.0 (SD 2.1) pmol/L, and 5.1 (SD 0.6) pmol/L, respectively. No food groups were associated with iodine intake and neither was gender, age, education level nor length of residence in Norway. In conclusion, this study showed that iodine intake was low, and a considerable proportion of the Somali population studied had sub-optimal iodine status. Monitoring of iodine status should be prioritised and measures to ensure adequate iodine intake, particularly among vulnerable groups initiated.

Highlights

Iodine is a trace element that is essential for humans
Fortification of animal fodder began in the early 1950s (2 mg/ kg), and from this followed a heightened concentration of iodine in milk and dairy products, which contributed to the eradication of endemic goiter and the prevention of iodine deficiency disorders (IDD) [6]
Norway is a nation with traditional high levels of milk consumption, and milk, dairy products, fish and fish products have since provided the main sources of iodine in the diet of Norwegians, contributing with about 80% of total iodine intake [7]

Summary

Introduction

Iodine is a trace element that is essential for humans. Low iodine intake may lead to numerous negative health outcomes, collectively named iodine deficiency disorders (IDD) [2]. The soil in the Nordic regions has by nature little iodine and IDD, including visible goiter, was previously endemic in inland areas where the consumption of saltwater fish was low [4,5]. Fortification of animal fodder began in the early 1950s (2 mg/ kg), and from this followed a heightened concentration of iodine in milk and dairy products, which contributed to the eradication of endemic goiter and the prevention of IDD [6]. Norway is a nation with traditional high levels of milk consumption, and milk, dairy products, fish and fish products have since provided the main sources of iodine in the diet of Norwegians, contributing with about 80% of total iodine intake [7]

Objectives

Results

Conclusion