Studying iodine intake of Portuguese children school meals

Abstract

Iodine is an essential trace element, and its nutritional importance is well established. The iodine content of school meals of Portuguese children aged between 6 and 10 years (collected in the metropolitan area of Lisbon) was analyzed by ICP-MS. The samples were cooked with and without iodized salt and additionally some complementary foods were purchased as supplements to the main meals or to the other meal along the day. The results report six meals per day and they suggest that at least one main meals (lunch or dinner) prepared with iodized salt is enough to reach the recommended daily iodine intake (AI), 90 µg/day, not exceeding the tolerable upper intake (UL) level of 300 µg/day. When both main meals are cooked without iodized salt, 11 % of the hypotheses present an iodine content less than 90 µg/day. However, when lunch and dinner are prepared with iodized salt, 1 % exceeds the value of the UL. The food groups with the highest levels of iodine are daily products and fish. These results presuppose a balanced diet without any dietary restrictions. So, for ideological or medical reasons, special attention must be paid to diets with some limitations, such as vegetarian, lactose or high content of proteins free diets.