What is one of the major environmental causes of intellectual disability in developing countries?

Iodine deficiency is recognized as one of the significant environmental causes of intellectual disability, particularly in developing countries. Iodine is essential for the production of thyroid hormones, which are crucial for normal brain development, especially during pregnancy and early childhood. When there is insufficient iodine intake, it leads to impaired neurological development, which can result in cognitive deficits and intellectual disabilities.

In many developing regions, access to iodine-rich foods, such as seafood and iodine-fortified salt, may be limited, increasing the risk of deficiency. This can have widespread implications for public health, as even mild deficiency during critical periods of development can negatively affect cognitive outcomes.

Other environmental factors, such as heavy metal exposure, substance abuse, and malnutrition, also contribute to intellectual disabilities, but iodine deficiency stands out for its specific impact on neurodevelopment in vulnerable populations, particularly where dietary sources of iodine are inadequate.