Americans are getting less iodine in their diet, putting them at increased risk of mental retardation, according to Doctor Joseph Hollowell from the Centers of Disease Control and Prevention. A study, published this past fall in the Journal of Clinical Endocrinology and Metabolism, reports finding that the amount of iodine concentrations in urine tests have dropped by more than 50% since the 1970’s.

The researchers had sampled almost 34,000 Americans and found that 12% of those tested had low levels of iodine in their urine. The number of people with insufficient iodine had more than quadrupled during the last two decades.

Iodine is a crucial nutrient for production of thyroid hormone, which plays an important role in brain development . If a pregnant mom is deficient in iodine, her fetus may be impacted. When a child under aged four does not get enough iodine it is equally critical. These are the time frames when a person’s brain is developing.

The mineral iodine is missing from the soil in many parts of world. This is the same soil used to grow the food for the animals and humans which live within the region. It should not be surprising that such soil would result in plants and vegetables that do not contain iodine. That also applies to weeds, trees, and other vegetation.

Humans consume plants, vegetables, and often the meat from animals. Since the animals used for food by humans commonly have consumed plants, vegetables, weeds, grasses and tree leaves, it follows that in locales where iodine does not exist within the soil, the normal method for a human to obtain iodine would not work. Humans, and also animals, would be deficient in iodine.

If a country or a large area does not have sufficient iodine within its soil, iodine deficiency cannot be eliminated by changing dietary habits or eating certain kinds of foods grown within that area. The correction has to be achieved by supplying iodine through an external source. In the United States, this was done by fortifying the commonly used mineral, salt. Salt is one of the few commodities that comes close to being universally consumed daily by all sections of society irrespective of economic level.

Early in this century, endemic goiter had been wide spread in the Great Lakes area. It already was well known that goiter was a easy disease to prevent through the provision of adequate amounts of iodine. Iodized salt was introduced in 1924. Twenty five years after starting this volunteer program of using iodized salt, the average goiter rate in this country had dropped from 35% to less than 2%.