Selenium & Goiter

Selenium is a mineral found in meat, nuts and enriched grain products that is essential for good health, although your body only needs small amounts. One of its important functions is to help your thyroid make and regulate iodine. If iodine levels get out of balance, it can cause an abnormal growth in your thyroid called a goiter, which is why maintaining a proper selenium balance is critical.

Goiters

Your thyroid is a small butterfly-shaped gland below the Adam's apple in your neck. The thyroid uses iodine to make hormones called T4 and T3 that oversee your body's temperature, metabolism, pulse, digestive functions and even your mood. When an iodine deficiency leads to low levels of T4 and T3, it causes a goiter to swell visibly in your neck. Traditional treatment involves hormone replacement drugs, anti-inflammatories, radioactive iodine or surgery to remove the thyroid.

Selenium Benefits

Your thyroid contains a higher concentration of selenium than any other organ in your body. Selenium's benefits are primarily due to its antioxidant properties; it fights damage to your cells caused by free radicals that lead to chronic diseases including cancer, heart disease and thyroid disease. Selenium is also essential for the production of an enzyme that breaks down estrogen, and a selenium deficiency can lead to excessive amounts of estrogen, depressing thyroid function.

Scientific Evidence

Selenium supplements protected against goiter and thyroid tissue damage in a 2003 study from France of 792 men and 1,108 women, although the effects were found primarily in women, as reported in the "European Journal of Endrocrinology." Scientists also studied the high rates of goiter in Uganda, where widely-available iodized salt meant that iodine deficiency could not explain the goiters. The results of the study, published in July 2011 in the "World Journal of Surgery," found that low selenium levels led to significantly higher goiter rates in both men and women.

Contradictory Research

A German research team published a study in 2006 in the "European Journal of Endocrinology" that found no link between selenium levels and thyroid volume, blaming the incidents of goiters on low iodine levels alone. Polish scientists investigated possible interactions between selenium and iodine metabolism in children with goiters. The study's conclusion, published in "Environmental Health Perspectives" in 2000, was that selenium had a possible link to goiters in girls but had no effect whatsoever in boys.

Considerations

The Institute of Medicine of the National Academy of Sciences established the tolerable upper intake level for selenium at 400 micrograms per day for adults. Excessive amounts of selenium from supplements can cause a toxic condition called selenosis, with gastrointestinal problems, hair loss, white blotchy nails, garlic breath odor, fatigue, irritability and mild nerve damage. Don't take selenium supplements for a goiter unless recommended by your doctor.