Expand and explain IDD.

IDD stands for Iodine Deficiency Disorders, which refer to a range of health problems caused by insufficient iodine intake. Iodine is an essential trace mineral required for the synthesis of thyroid hormones, which regulate metabolism and play a crucial role in growth and development, particularly of the brain and nervous system.

When iodine intake is inadequate, the thyroid gland becomes unable to produce enough thyroid hormones, leading to various disorders collectively known as IDD. The most common IDD include:

1. Goiter: Enlargement of the thyroid gland in response to prolonged stimulation by thyroid-stimulating hormone (TSH) due to insufficient iodine.

2. Hypothyroidism: Reduced thyroid hormone production, which can cause symptoms such as fatigue, weight gain, cold intolerance, and impaired mental function.

3. Cretinism: Severe mental and physical retardation in infants and children due to maternal iodine deficiency during pregnancy.

IDD is a significant public health concern, particularly in regions where the soil is low in iodine and access to iodine-rich foods like seafood is limited. The most effective strategy to prevent IDD is universal salt iodization, where iodine is added to salt to ensure an adequate intake across populations. Other approaches include dietary diversification and supplementation programs targeted at vulnerable groups such as pregnant women and young children. Regular monitoring and surveillance of iodine status are essential to prevent and address IDD effectively.