Possible symptoms of having too much iodine in the body include a burning sensation in the mouth, throat or stomach, a weak pulse, diarrhea, and vomiting, according to the Office of Dietary Supplements. People who consume excessive amounts of iodine may also suffer stomach pain, nausea and coma.
The effects of high iodine levels on the body are similar to the symptoms of iodine deficiency, notes the Office of Dietary Supplements. People who take too little or too much iodine are prone to develop goiter, an inflamed thyroid gland and thyroid cancer.
The maximum daily intake of iodine for adults is 1,100 micrograms and 900 micrograms for teens aged 14 to 18, states the Office of Dietary Supplements. Children from 9 to 13 years old should not take more than 600 micrograms of iodine, and children from 4 to 8 years old should not exceed an intake of 300 micrograms. Those who take iodine for medical problems, such as iodine deficiency, may have different iodine intake limitations.
Iodine deficiency causes the body to produce inadequate amounts of thyroid hormone, says the Office of Dietary Supplements. Severe iodine deficiency can lead to permanent damage to a fetus, including stunted growth and mental retardation. It is essential for people to obtain proper amounts of iodine from a variety of food sources, especially fish, dairy products, fruits and vegetables.