Iodine has also been used to help increase energy level and utilization in cases of fatigue, mental sluggishness, and weight gain caused by hypothyroidism. Iodine itself will not help with weight loss if there is normal thyroid function. If weight gain results from iodine deficiency causing decreased thyroid activity, this hypothyroid condition may be improved with iodine followed by thyroid supplementation. Iodine solutions, such as iodine tincture or Betadine, are commonly used as antiseptics and can actually kill bacteria and fungi.

Because of the thyroid's role in fat and cholesterol metabolism, sufficient iodine and thus normal thyroid levels are thought to help reduce atherosclerosis potential. Also, iodine and thyroid may help maintain healthy hair, skin, and nails. It is possible that iodine deficiency increases the risk of certain cancers, such as breast, ovary, and uterus. Iodine levels may be low in people with fibrocystic breast disease; in this case, supplementation may improve this condition.

Potassium iodide has been used medicinally for problems of the skin and as an expectorant for bronchial congestion. Silver iodide has been used to seed clouds to bring rain, but this practice is considered ecologically unsound. Iodine supplements may help prevent uptake of radioactive iodine if that is present in the environment or in medical diagnostic procedures. If the thyroid were saturated with normal iodine, it would eliminate the radioactive molecules more rapidly.

Deficiency and toxicity: There is no significant danger of toxicity of iodine from a natural diet, though some care must be taken when supplementing iodine or using it in drug therapy. High iodine intake, however, may actually reduce thyroxine production and thyroid function. Excessive quantities of iodized salt, taking too many kelp tablets, or overuse of potassium iodide expectorants such as SSKI can cause some problems, but regular elevated intake of iodine is needed to produce toxicity. Some people have allergic reactions, mainly as skin rashes, to iodine products. Iodine supplementation may also worsen acne in some cases.

Deficiencies of iodine have been very common, especially in areas where the soil is depleted, as discussed earlier. Several months of iodine deficiency can lead to goiter and/or hypothyroidism. With decreased iodine, the thyroid cells and gland enlarge, creating a goiter, which may be noticed mainly by the swelling it causes in the base of the neck.

Goiter is usually associated with hypothyroidism, which is decreased thyroid function that leads to slower metabolism, fatigue, weight gain, sluggishness, dry hair, thick skin, poor mental functioning, decreased resistance to infection, a feeling of coldness, and a decrease in sexual energy. More advanced hypothyroidism may worsen these symptoms as well as create a hyperactive, manic state and hypertension, which is paradoxical because this may occur with an overactive thyroid as well. Iodine by itself usually will not cure goiter and hypothyroidism but often will slow their progression.

Goitrogens are substances that can induce goiter, primarily by interfering with the formation and function of thyroglobulin. Some natural goitrogens are soybeans, cabbage, cauliflower, and peanuts, especially when they