Abstract
Iodine is an important nutrient for human health and development, with seafood widely acknowledged as a rich source. Demand from the increasing global population has resulted in the availability of a wider range of wild and farmed seafood. Increased aquaculture production, however, has resulted in changes to feed ingredients that affect the nutritional quality of the final product. The present study assessed the iodine contents of wild and farmed seafood available to UK consumers and evaluated its contribution to current dietary iodine intake. Ninety-five seafood types, encompassing marine and freshwater fish and shellfish, of wild and farmed origins, were purchased from UK retailers and analysed. Iodine contents ranged from 427.4 ± 316.1 to 3.0 ± 1.6 µg·100 g−1 flesh wet weight (mean ± SD) in haddock (Melanogrammus aeglefinus) and common carp (Cyprinus carpio), respectively, being in the order shellfish > marine fish > freshwater fish, with crustaceans, whitefish (Gadiformes) and bivalves contributing the greatest levels. Overall, wild fish tended to exhibit higher iodine concentrations than farmed fish, with the exception of non-fed aquaculture species (bivalves). However, no significant differences were observed between wild and farmed Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and turbot (Psetta maxima). In contrast, farmed European seabass (Dicentrarchus labrax) and seabream (Sparus aurata) presented lower, and Atlantic halibut (Hippoglossus hippoglossus) higher, iodine levels than their wild counterparts, most likely due to the type and inclusion level of feed ingredients used. By following UK dietary guidelines for fish consumption, a portion of the highest oily (Atlantic mackerel, Scomber scombrus) and lean (haddock) fish species would provide two-thirds of the weekly recommended iodine intake (980 µg). In contrast, actual iodine intake from seafood consumption is estimated at only 9.4–18.0% of the UK reference nutrient intake (140 µg·day−1) across different age groups and genders, with females obtaining less than their male equivalents.
Highlights
Iodine is an essential trace element with an important role in the regulation of vertebrate development and metabolism, being necessary for the biosynthesis of the thyroid hormones thyroxine and tri-iodothyronine [1,2,3]
Delgado et al [38] found that mackerel and sardines (Sardina pilchardus) purchased from Portuguese markets tended to exhibit higher iodine contents in summer/autumn months compared to winter/spring
Data on the iodine contents of food are important in order to maintain food composition databases and estimate an individual’s intake status
Summary
Iodine is an essential trace element with an important role in the regulation of vertebrate development and metabolism, being necessary for the biosynthesis of the thyroid hormones thyroxine and tri-iodothyronine [1,2,3]. Deficiencies in iodine intake can result in a variety of known human health disorders that affect the thyroid (goitre), as well as cognitive development and function that can affect an individual at any stage during life from foetus to adulthood [1,4,5]. In the UK, the current RNI for adults is 140 μg·day−1 [6], slightly lower than the 150 μg·day−1 RNI for adults and ≥200 μg·day−1 RNI for pregnant and lactating women advocated by the World Health Organisation (WHO) and other health authorities [7,8,9,10] These allowances are mostly expected to be satisfied through dietary consumption. In the UK, as well as Western Europe in general, there is some concern that iodine intake has become mild to moderately inadequate, especially among more vulnerable groups such as young children and women of reproductive age, despite improvements in nutrition [4,5,11,12,13,14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
