A time to think about women’s health and children’s cognitive development

As the world marks World Iodine Deficiency Disorders (IDD) Day, a silent but serious nutrition challenge is re-emerging. Mild iodine deficiency is rising again across Europe and North America, especially among women of reproductive age and pregnant women, who need iodine in their diets both before and during pregnancy to help protect their future children.

In the United States, the proportion of women whose diets lack sufficient iodine nearly doubled between 2001 and 2018, with 46% of pregnant women now consuming inadequate levels [1]according to a recent study published in The Journal of Nutrition. The WHO/IGN 2024 Europe report found similarly concerning patterns, with pregnant women showing inadequate iodine status in 15 of 24 European countries with available data. These findings reflect a wider global trend as diets shift toward less dairy, more processed foods, and increasing use of non-iodized or specialty salts, putting women at growing risk of iodine deficiency.

Why iodine matters for women

Iodine is essential to produce thyroid hormones, which regulate metabolism, growth, and brain development. During pregnancy, a mother’s iodine intake directly affects the child’s neurological development. Even moderate to mild iodine deficiency can have long-term effects, including lower language and cognitive performance in children.

For women, inadequate iodine can also increase the risk of goitre, thyroid nodules, and hyperthyroidism, conditions that often appear later in life and place a financial burden on health systems.

A century of progress and the danger of complacency

It has been over a century since salt iodization began in Switzerland, setting in motion one of the world’s most successful public health interventions. Universal salt iodization has since protected billions of people, sharply reducing iodine deficiency and its impact on brain development and learning outcomes.

But recent data show that global progress is slowing, and in some regions, even reversing. The IGN Global Scorecard highlights a troubling pattern, noting that while iodine intake remains adequate in most countries, the number of countries classified as iodine deficient has risen again, from 19 in 2017 to 23 today.

What needs to happen next

The progress made in eliminating iodine deficiency can only be sustained through continued commitment and adaptation. As diets evolve and food systems change, policies and practices must keep pace to ensure that everyone receives enough iodine for healthy growth and brain development.

Governments must review and strengthen existing iodization programs and, where appropriate, stimulate the use of iodized salt instead of non-iodized salt in processed foods. Continued monitoring, enforcement, and communication are essential to ensure national programs remain effective.

Health practitioners are key to prevention. By advising patients of iodine’s importance and advising on dietary sources, they can help reduce the risk of deficiency, particularly among women of reproductive age.

Women, especially those planning to become pregnant, should be informed and empowered to protect their own health and that of their children. Choosing iodized salt is a simple step with lifelong benefits.

Iodine deficiency is one of the world’s most preventable causes of cognitive impairment and its impact is simple, affordable, and proven. As we mark World IDD Day, the message is clear: Protecting women’s iodine nutrition protects every child’s right to a healthy brain and a brighter future.

[1] (Lieberman HR, Mathews RS, Fulgoni VL III, 2025)