Global IDD Prevention Day is celebrated each year on October 21, to raise awareness of iodine deficiency and its devastating effects on brain development.

The day celebrates the tremendous global progress against IDD since national salt iodization programs first began in the 1990s. But despite these efforts, 240 million school-age children worldwide are still not getting enough iodine in their diets.

The IDD Prevention Day serves as a reminder global effort against IDD must be sustained, until all children have optimal iodine nutrition and can reach their full cognitive potential.

See how the day was celebrated around the world: