*2.4. Iodine*

Iodine is a vital constituent of the thyroid hormones, thyroxine (T4), and triiodothyronine (T3) and essential for normal growth, development, and metabolism. According to the Food and Nutrition Board, Institute of Medicine, the RDI for I is 150 μg/day for both adult males and females (https://ods.od.nih.gov/Health\_Information/Dietary\_Reference\_Intakes.aspx). Deficiency of iodine causes hypothyroidism, goiter, cretinism, mental retardation, and reduced fertility and is accountable for increased prenatal death and infant mortality [49–51]. Deficiency during pregnancy can cause cognitive impairment in the o ffspring as it is critical for brain development [52,53].

Deficiency of iodine in human populations is di fferent from other micronutrients as it is predominant in developing as well as developed countries [54–56]. This could be due to the low concentration of this mineral in agricultural soils and cereal-based foods [55].
