Congenital iodine deficiency syndrome those areas without outside food sources are most at risk of iodine deficiency diseases. Iodine deficiency results in the impairments in varying degrees of physical and mental development. It also causes gradual enlargement of the thyroid gland, referred to as a goiter. It is being combated in many countries by public health campaigns of iodine administration. Congenital hypothyroidism can be endemic, genetic, or sporadic. If untreated, it results in mild to severe impairment of both physical and mental growth and development. Poor length growth is apparent as early as the first year of life. Adult stature without treatment ranges from
Iodine demonstrated that these animals could survive after eating a 14000 mg/kg dose). Excess iodine can be more cytotoxic in the presence of selenium deficiency. Iodine supplementation in selenium-deficient populations is, in theory, problematic, partly for this reason. The toxicity derives from its oxidizing properties, through which it denaturates proteins (including enzymes). Elemental iodine is also a skin irritant, and direct contact with skin can cause damage and solid iodine crystals should be handled with care. Solutions with high elemental iodine concentration, such as tincture of iodine and Lugol's solution, are capable of causing tissue damage if used in prolonged cleaning