COLLOIDAL MINERALS: IODINE

IODINE
IMPORTANCE:
Aids in the development and functioning of the thyroid gland; regulates the body's production of energy; helps burn excess fat by stimulating the rate of metabolism; mentality, speech, the condition of the hair, skin, & teeth are dependent upon a well-functioning thyroid gland.

Iodine is a key component of the hormone thyroxin, produced by the thyroid gland. Thyroxin regulates the level of metabolism and is essential for normal development of the fetus. Iodine is absorbed from the digestive tract and carried by serum proteins to the thyroid gland where it is stored in thyroxin and its precursors.

IODINE DEFICIENCY SYMPTOMS:
May result in an enlarged thyroid gland, slow mental reaction, dry skin & hair, weight gain, loss of physical & mental vigor.

An iodine deficiency produces compensatory hypertrophy of the thyroid gland, resulting in a goiter. Cretinism is a consequence of severe iodine deficiency in early pregnancy. Cretins are feeble-minded dwarfs with characteristic faces and gait. Mild to moderate maternal deficiency during pregnancy causes lesser degrees of neurological damage, particularly poorer cognitive performance and hearing impairment. Initially, goiters are soft and diffuse but become fibrotic in older individuals. Nodular goiters are a common result of maternal iodine deficiency. Thyroxine deficiency in adults results in hypothyroidism characterized by a low metabolic rate.

IODINE Prevention and treatment:
Goiter can be prevented by the addition of potassium iodate or iodide to salt for human consumption (1 part iodine to 20,000 to 80,000 parts salt), depending on whether endemic goiter is a public health problem. In the United States salt contains 76 mg I2/g. Potassium iodate is used more frequently as it has the advantage of being stable in crude moist salt even under unfavorable conditions. Bread and water are alternate vehicles for iodine. Goiters that have not become fibrotic disappear when iodine is given in any of the forms described above. If a goiter appears during pregnancy, treatment will be too late to avoid damage to the fetus.

Diet recommendations: The Recommended Dietary Allowances are as follows: infants, 40-50 mcg; 1-3 yrs, 70 mcg; 4-6 yrs, 90 mcg; 7-10 yrs, 190 mcg; over 11 yrs, 150 mcg; pregnancy, 175 mcg; and lactation, 200 mcg.

IODINE Food sources:
Iodine content of food and water depends on the supply of iodine in the environment. Glaciered, mountainous or heavy rainfall areas are likely to be low in iodine. Some plants, including cabbage, Brussels sprouts, legumes, and cassava contain goitrogenous substances that interfere with iodine absorption. This is of public health concern only when any or several of these foods are regularly consumed in relatively large amounts, particularly if the intake of iodine is marginal or low.

Toxicity:
Chronically excessive iodine intakes can also be a cause of goiter and hypothyroidism. In addition, a small increase in thyrotoxicosis, although it is usually not detected, may be the inevitable outcome of increasing the iodine intake of a population which has had a low intake for many generations.

Recent research:
Large studies in China, Ecuador, and Zaire have demonstrated a lower distribution of I.Q. in the populations in villages with endemic goiter. The use of iodized salt has produced improvements.

For further information:

Hetzel B.S. (1989). The Story of Iodine Deficiency: An International Challenge in Nutrition. Oxford University Press, Delhi

Stanbury J.B., ed. (1994). The Damaged Brain of Iodine Deficiency. Cognitive Communications Corp., Elmsford, NY:

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