Iodine 101: Why This Essential Nutrient Matters More Than Ever

Iodine is a trace element that plays an outsized role in human health. Despite being required in only microgram amounts each day, deficiencies are increasingly common in both North America and across the globe. Understanding why iodine is important, why deficiency has become more prevalent, and how changes in our food supply have contributed to this problem is the first step toward protecting long-term health.

Why Iodine Is Essential for Health

Iodine is a critical component of thyroid hormones (thyroxine, T4, and triiodothyronine, T3). These hormones regulate energy metabolism, brain development, and growth throughout life. Adequate iodine is especially important during pregnancy and early childhood, when deficiency can impair neurodevelopment and lower IQ scores.

Beyond the thyroid, iodine also supports skin integrity, immune defense, and reproductive health. Clinical studies show that iodine deficiency increases the risk of goiter, hypothyroidism, fatigue, weight gain, and impaired cognitive performance (Zimmermann & Boelaert, 2015).

The Incidence of Iodine Deficiency

Global Perspective

According to the World Health Organization, iodine deficiency remains one of the most widespread nutritional problems worldwide, affecting nearly 2 billion people. Approximately 30% of the global population is considered at risk of inadequate intake (Pearce et al., 2013).

North America

Although North America was once considered iodine-sufficient, deficiency has re-emerged in recent decades. Data from the National Health and Nutrition Examination Survey (NHANES) show that median urinary iodine concentrations in the United States have dropped by more than 50% since the 1970s (Caldwell et al., 2005). Vulnerable groups include pregnant women, vegans, and individuals who avoid dairy or iodized salt.

Canadian surveys similarly suggest that mild iodine insufficiency may be present in women of reproductive age, particularly those relying on non-iodized specialty salts such as sea salt or Himalayan salt (Anderson et al., 2010).

Why Our Food Supply Is Low in Iodine

Modern agricultural and food processing practices have significantly reduced iodine content in the food chain:

1. Decline in iodized salt use: While table salt fortification programs were effective in the mid-20th century, consumer shifts toward gourmet and “natural” salts, combined with public health messaging to reduce sodium intake, have lowered iodine intake.

2. Changes in dairy processing: Historically, iodine entered the food supply through iodine-based disinfectants used in dairy farming. With changes in sanitation practices and replacement by other chemicals, milk now contains far less iodine than it once did (Bath et al., 2012).

3. Crop soil depletion: Many agricultural soils are naturally low in iodine. Industrialized farming practices often do not replenish iodine, leading to crops with reduced trace mineral content (Weng et al., 2009).

4. Reduced seafood intake: While seaweed, fish, and shellfish remain rich sources of iodine, consumption patterns in North America have shifted away from these foods.

Key Takeaways

• Iodine is essential for thyroid hormone production, brain development, metabolism, and immune health.

• Deficiency is re-emerging in North America and still affects nearly two billion people worldwide.

• Agricultural practices, shifts in food processing, and reduced iodized salt use have all contributed to lower iodine levels in our diet.

Ensuring adequate iodine intake is more important than ever in today’s food environment. Supplementation with safe, effective products such as Iodine Pure can help bridge the gap and protect long-term health.

Written By Dr. Evan Lewis

References

• Anderson, M., et al. (2010). Iodine intake in Canadian women of reproductive age. Canadian Journal of Dietetic Practice and Research, 71(1), 9–14.

• Bath, S. C., et al. (2012). Iodine concentration of milk-alternative drinks available in the UK in comparison with cows’ milk. British Journal of Nutrition, 107(7), 935–940.

• Caldwell, K. L., et al. (2005). Urinary iodine concentration: United States National Health and Nutrition Examination Survey 2001–2002. Thyroid, 15(7), 692–699.

• Pearce, E. N., Andersson, M., & Zimmermann, M. B. (2013). Global iodine nutrition: Where do we stand in 2013?Thyroid, 23(5), 523–528.

• Weng, H., et al. (2009). Iodine biofortification of vegetable crops: A review. Agronomy for Sustainable Development, 29(4), 465–478.

• Zimmermann, M. B., & Boelaert, K. (2015). Iodine deficiency and thyroid disorders. The Lancet Diabetes & Endocrinology, 3(4), 286–295.