non-metallic trace element, needed for the normal metabolism of cells. in particular for the synthesis of thyroid hormones. It is used as mild antiseptic. Deficiency may case an enlarged thyroid gland (goitre), dry skin, hair loss, fatigue and slowed reflexes. Anecdotal evidence exists that long term Iodine deficiency may cause breast cancer. Large doses of iodine (radioiodine therapy and supplement overdose) are dry mouth, taste change, iodine-induced thyrotoxicosis. More than adequate or excessive iodine intake may lead to hypothyroidism and autoimmune thyroiditis. Main sources are seaweed, iodized salt, seafood, dairy.
