Iodine deficiency is often seen as a problem of the past, but this isn’t entirely true. During the 20th century, the iodisation of salt became one of the most effective public health interventions for preventing conditions caused by a lack of this mineral, including goiter (enlargement of the thyroid gland) and preventable damage to neurological development. The World Health Organization (WHO) still views iodised salt as a safe and effective strategy, while UNICEF notes that it is the most widely used way of improving iodine intake worldwide. However, the success of this simple measure means iodine has all but disappeared from public debate. And today, in several countries, signs of insufficient intake are once again being detected in certain groups, particularly in pregnant or breastfeeding women and people on restrictive or poorly planned diets.…