Iodine is important for brain neuron development during pregnancy, and during childhood development, including an effect on IQ. It is required in small amounts to make thyroid hormones. The thyroid gland holds 70-80% of the iodine in the body. Sources include iodized salt (most table salt), seafoods, dairy products, grains, eggs, and poultry.
Quick Facts
-Required in small amounts to make thyroid hormones
-Brain neuron development during pregnancy, and during childhood development, including an effect on IQ [81]
-The thyroid gland holds 70-80% of iodine in the body
RDI
Males 19 – 30 yrs: 150 μg
Females 19 – 30 yrs: 150 μg
[128]
Pregnant women 220 μg / day
Breast-feeding women 290 μg / day
Deficiency
-An estimated 30% of the world’s population has insufficient iodine intake
-Impairs thyroid hormone production leading to hypothyroidism
-Can result in a large range of disorders from thyroid gland enlargement to severe physical and mental retardation
-Symptoms first show an enlarged thyroid gland (goiter), and other symptoms include fatigue, weight gain, cold intolerance, and constipation. Even poorer social and economic achievements due to lower educability, reduced motivation and productivity are a result
-Pregnant women are most vulnerable to iodine deficiency which also causes improper fetus growth
Toxicity
-An upper limit of 1,100 μg / day is recommended
-Rare, and only occurs in cases where many grams are taken (millions of μg). Symptoms include burning in the mouth, throat, and stomach, fever, nausea, vomiting, diarrhea, a weak pulse, cyanosis and coma
-Doses of 150 – 200 μg / day are correlated with an increased risk of hyperthyroidism, which includes symptoms of weight loss, tachycardia, muscle weakness, and skin warmth. However, benefits largely outweigh risks [207]
Sources
Iodized salt (most table salt), seafoods [81] Dairy products, grains, eggs, and poultry [207]
