Iodine

Iodine is an essential element for life. In our body only trace amounts of iodine is present.

Iodine is a constituent of the thyroid hormones, thyroxine iodine containing hormones regulate your metabolic rate (T4) and triiodothyronine (T3). Thyroid hormones regulate the basal metabolic rate in the body.

However, 70% of the body's iodine is distributed in other tissues, including mammary glands, eyes, gastric mucosa, the cervix, and salivary glands, where it has other important functions.

Sources

Iodized salt - iodide fortified table salt - is the main food source of iodine. Seafood is naturally rich in iodine.

Cod, sea bass, haddock, perch, kelp and plants grown in iodine-rich soil are good sources of iodine. Dairy products also contain iodine.

Daily intake

The recommended daily intake of iodine is 150 micrograms for adults, 220 micrograms for pregnant women and 290 micrograms for lactating women.

These intakes are necessary to ensure a normal basal metabolic rate and optimal function of all processes in which iodine have a role in the body.

Deficiency

Iodine deficiency gives rise to hypothyroidism with extreme fatigue, goitre (swelling in the thyroid gland), mental slowing, depression, weight gain, and low basal body temperatures.

Iodine deficiency is the leading cause of preventable mental retardation, which occurs primarily when babies or small children lack iodine. Iodine deficiency is a serious public health problem in some developing countries.

The addition of iodine to table salt has largely eliminated iodine deficiency in the wealthier nations.

Excess

The tolerable upper intake level for adults is 1100 micrograms/day.

Acute iodine poisoning is rare and occurs only if taken orally in a large amount.

The lethal dose for adults is 2–3 grams of iodine. Symptoms of acute iodine poisoning include burning of the mouth, throat, and stomach, fever, nausea, vomiting, diarrhea, weak pulse and coma.

References: 1 , 2 , 3 , 4