American Thyroid Association Issues Call for Universal Salt Iodization

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In a statement published in the February 2017 issue of the journal Thyroid, the American Thyroid Association (ATA) issued a call for universal salt iodization. Universal salt iodization is defined as the addition of iodine to all salt that is intended to be consumed by humans. The goal of the ATA in issuing is to help alleviate the negative health effects of iodine deficiency.

Iodine and the Thyroid

Iodine is an essential nutrient that is required by the body in order to produce thyroid hormone.

The body does not make iodine so it must be ingested, usually through food grown in iodine-rich soil, seafood, or through iodization of salt.

Iodine deficiency—and its extreme form iodine deficiency disorders (IDD)—is associated with cretinism, an irreversible condition that causes severe growth impairment and mental retardation. IDD is in fact the leading preventable cause of mental retardation in the world. The ATA has reported that an estimated 40 percent of the world’s population is currently at risk for iodine deficiency.

A deficiency of iodine is also associated with thyroid enlargement (goiter), an under active thyroid (hypothyroidism), recurrent miscarriage, and pregnancy loss, among other complications and health conditions. It’s also been shown in research that iodine deficiency in a woman during pregnancy can cause intellectual and cognitive deficits in her children. According to the ATA statement: “The long-term and potentially lifelong personal and social impact of this cannot be overemphasized.”

The  Geography of Iodine Deficiency

Food that is grown in areas that were once covered by oceans tend to have higher iodine concentrations—and as a result, populations that are not notably iodine deficient. Inland or high-elevation areas that have lower iodine concentrations in their soil—and that provide less access to seafood—are more likely to have lower levels of iodine in their food supply and are at greater risk of IDD.

According to researchers, the only countries that currently appear to have what’s called “sustainable iodine sufficiency” include the United States, Canada, Norway, Sweden, Finland, Switzerland, Austria, Bhutan, Peru, Panama, Macedonia, and Japan.

Areas of specific concern include central Africa and Asia, where there are significant populations with severe iodine deficiency, along with the Himalayas, the European Alps, the Andes, and parts of Eastern Europe. Other areas of Europe also have some degree of iodine deficiency.

The ATA's Points on Universal Salt Iodization

The ATA statement made several other key points about universal salt iodization:

  • Universal salt iodization is the most effective way to prevent iodine deficiency and iodine deficiency disorders.
  • Salt was initially chosen as the vehicle for iodine fortification efforts because it is consumed in relatively stable amounts by virtually every individual and population group on a daily basis; the technology required for salt iodization is relatively simple; in many regions salt production is consolidated in relatively few centers, which facilitates monitoring and enforcement; and salt iodization is inexpensive.
  • There is evidence that universal salt iodization needs to be legislated and strictly enforced at a national level in order to be effective.
  • Monitoring—in particular looking at urinary iodine levels in populations—is essential as a way to ensure that the iodine intake is sufficient.
  • Universal salt iodization has been recommended by the WHO, Iodine Global Network, and UNICEF.

The WHO has been promoting universal salt iodization since 1993. They chose salt as the tactic to address IDD for two key reasons:

It is widely available and consumed in regular amounts throughout the year, and because the cost of iodizing it is extremely low – only about US$ 0.05 per person per year.

According to the WHO, an estimated 66 percent of households worldwide now have access to iodized salt, but more than 2 billion people in the world still have insufficient iodine intake, and a third of them are children.

What Is the Recommended Intake of Iodine?

The World Health Organization recommends:

  • 90 mcg of iodine daily for infants and children up to 5 years
  • 120 mcg for children 6 to 12 years
  • 150 mcg daily for children ≥12 years and adults
  • 250 mcg daily during pregnancy and lactation

The United States Institute of Medicine recommended minimum daily intake of iodine is similar:

  • 90 mcg daily for children 1 to 8 years old
  • 120 mcg for children 9 to 13 years old
  • 150 mcg daily for older adolescents and nonpregnant adults
  • 220 mcg for pregnant women
  • 290 mcg for lactating women

If you're concerned about your iodine intake, talk to your doctor about having your levels tested and, if needed, finding solutions to meet your needs.

Sources:

American Thyroid Association. Iodine Deficiency. http://www.thyroid.org/iodine-deficiency/

Pearce Elizabeth N.. Thyroid. February 2017, 27(2): 137-137. doi:10.1089/thy.2016.0678.

Vitti, P., “Iodine deficiency disorders,” UptoDate. Jan 31, 2017. http://www.uptodate.com/contents/iodine-deficiency-disorders

World Health Organization. “Iodine Deficiency.” http://www.who.int/nutrition/topics/idd/en/

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