Seafood intake in accordance with the dietary recommendations contribute significantly to the iodine intake in 5-year-old children – a cross-sectional study from Bergen, Norway

A child’s diet can significantly impact lifelong health. Surveys show adequate iodine intake in pre-school children, but the decreasing milk and seafood consumption in Norway poses a risk for inadequate iodine intake. The objective of the study was to assess dietary intake of the most important iodine sources in 5-year-old-children (n = 80) in Bergen, Norway. The present cross-sectional study serves as a follow-up to a randomized controlled trial (RCT) assessing the effect of cod consumption during pregnancy on iodine status. The caregivers answered an online food frequency questionnaire with focus on dietary iodine sources. The children’s median iodine intake of 80 µg/day was equal to the provisional average requirement (AR). All children consumed both seafood, milk, and dairy products and these two food groups provided 25 and 65% to the iodine AR, respectively. Milk alone, either as beverage or added to cereal products, contributed 50% of AR. The children consumed weekly 2.1 ± 1.0 dinner meals of seafood. Most of the seafood dinners were lean fish, either fish products (56%) or fish fillet (19%). Fatty fish accounted for 24% of the dinner intake, while shellfish was seldom consumed by the children (2%). None of the children used iodine supplements. Seafood was consumed twice as frequently as red meat. The substantial intake of lean fish leads to a higher iodine intake from this food category compared to other national studies. This finding is particularly interesting considering that the mothers were participants in an RCT emphasizing lean fish consumption.