Iodine

Iodine is a trace element naturally found in marine soils and concentrated in certain foods such as seaweed, saltwater fish and dairy products. Since the human body cannot synthesise it, iodine must be provided entirely through diet or supplementation. Iodine plays a central role in the production of thyroid hormones — thyroxine (T4) and triiodothyronine (T3) — which contribute to normal energy metabolism and ordinary cognitive function. These hormones are particularly important during foetal life, where they are involved in the development of the central nervous system, and remain essential throughout adolescence and adult life. In Europe, dietary iodine intake is often insufficient, especially in inland regions far from the coast. Appropriate supplementation helps meet the recommended daily requirements, set at 150 µg per day for adults and at higher levels for pregnant or breastfeeding women.