The Silent Lifesaver: Why is iodized salt so important?

November 10, 2025 •

3 min read

Worldwide, iodine deficiency affects an estimated two billion people and is the leading preventable cause of intellectual and developmental disabilities. Understanding why is iodized salt so important is crucial, as this simple dietary addition is one of the most effective and low-cost public health interventions in history.

Quick Summary

Iodized salt provides a vital micronutrient, iodine, which the body cannot produce on its own. It is critical for proper thyroid function, regulating metabolism, and supporting crucial fetal and infant brain development. This preventative measure has successfully combated widespread iodine deficiency disorders like goiter and cretinism.

Key Points

Essential Mineral: Iodine is a crucial trace mineral that the body cannot produce, making it an essential part of the diet.
Thyroid Function: Iodine is required for the thyroid gland to produce hormones that regulate metabolism, heart rate, and body temperature.
Brain Development: The most critical role of iodine is supporting the healthy development of the brain and nervous system in fetuses and infants.
Prevents Deficiency Disorders: The addition of iodine to salt prevents conditions like goiter, hypothyroidism, and severe mental impairments such as cretinism.
Public Health Success: Salt iodization is a simple, cost-effective public health measure that has dramatically reduced iodine deficiency worldwide.
Moderation is Key: Despite its benefits, all salt, including iodized salt, should be consumed in moderation to prevent excessive sodium intake.

The Crucial Connection: Iodine and the Thyroid Gland

At the heart of iodized salt's importance is the thyroid gland, a butterfly-shaped endocrine gland located at the base of the neck. This gland is responsible for producing the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which are essential for regulating numerous bodily functions. These functions include:

Metabolism: How the body uses energy from food.
Heart Rate and Blood Pressure: Maintaining a steady, healthy cardiovascular system.
Body Temperature: Regulating internal heat.
Overall Growth and Development: Especially vital during pregnancy and infancy.

Iodine is an essential building block for these hormones, and because the human body cannot produce it, a consistent dietary source is required. Insufficient iodine leads to the thyroid struggling to produce enough hormones, resulting in Iodine Deficiency Disorders (IDDs).

The Consequences of Iodine Deficiency

Insufficient iodine can lead to health complications, posing the greatest risk to pregnant women and young children. One visible sign is an enlarged thyroid gland (goiter). Chronic deficiency can cause an underactive thyroid (hypothyroidism) with symptoms like fatigue and weight gain. Iodine deficiency is a significant preventable cause of brain damage and cognitive impairment globally. For pregnant and breastfeeding women, adequate iodine is vital for fetal brain development. Severe maternal deficiency can lead to complications, including cretinism.

A Public Health Triumph: The History of Salt Iodization

Before widespread iodization, iodine deficiency was a severe problem in many areas, particularly inland regions with low-iodine soil. Adding iodine to salt became a simple, cost-effective solution. Salt iodization has been a successful public health measure, supported by organizations like the World Health Organization. Salt is a stable, inexpensive, and widely consumed vehicle for ensuring iodine intake.

Iodized vs. Non-Iodized: A Nutritional Comparison

Different salts have varying nutritional benefits.


Feature	Iodized Table Salt	Non-Iodized Salts (Sea, Kosher, Pink Himalayan)
Iodine Content	Yes, fortified with added iodine.	No, or only trace amounts that are unreliable for meeting daily needs.
Processing	Highly refined and processed to ensure uniform texture and purity.	Varies, can be minimally processed with larger crystals.
Culinary Use	All-purpose seasoning; preferred for baking and cooking where iodine is not a concern for flavor.	Preferred for specific culinary applications where a unique texture or flavor is desired, such as finishing dishes.
Trace Minerals	Minerals are typically removed during the refining process.	May contain trace minerals, but not in high enough quantities to be considered a reliable source of iodine.
Health Impact	A primary dietary source of iodine, crucial for preventing IDDs.	Does not protect against iodine deficiency; can be a risk for those without other iodine sources.

Who Needs Iodized Salt the Most?

While a balanced diet is ideal, some groups are at higher risk of deficiency.

Pregnant and Breastfeeding Women: Iodine needs increase to support infant development.
Vegans and Vegetarians: May rely more on iodized salt or supplements due to avoiding dairy and seafood.
Residents of Iodine-Poor Regions: Should use iodized salt to compensate for low intake from local food.

The Importance of Moderation and Other Sources

Iodized salt is effective and safe for most people, but moderation is key due to sodium intake risks. The WHO recommends less than 5 grams of salt daily.

Other iodine sources include:

Seafood: Cod, shrimp, and tuna.
Dairy Products: Milk, cheese, and yogurt.
Eggs: A reliable source.
Seaweed: Very high in iodine, but monitor intake.

For more details, consult sources like the National Institutes of Health.

Conclusion: The Small Change with a Big Impact

Iodized salt is a critical public health tool against iodine deficiency, supporting thyroid function and vital brain development. Despite modern dietary changes, iodized salt remains crucial for health and preventing the return of IDDs. A small choice can have a lasting impact.

Note: Continued vigilance is needed due to processed foods using non-iodized salt and a trend toward unfortified salts.

National Institutes of Health (NIH) Office of Dietary Supplements

Frequently Asked Questions

The main function of iodine is to enable the thyroid gland to produce thyroid hormones (T4 and T3). These hormones are responsible for regulating metabolism, energy usage, and overall growth and development.

Iodine deficiency can lead to various health problems, including an enlarged thyroid gland (goiter), an underactive thyroid (hypothyroidism), and serious developmental issues, particularly in infants and children.

No, non-iodized salts like sea salt, kosher salt, and Himalayan pink salt are not reliable sources of iodine. While they may contain trace amounts, it is not sufficient to meet daily nutritional needs.

Pregnant women require approximately 220 micrograms (mcg) of iodine daily, while breastfeeding women need around 290 mcg. This is significantly more than the 150 mcg recommended for most adults.

Yes, iodized salt had a profound historical impact, particularly in regions known as 'goiter belts' in the early 20th century. Its introduction as a public health measure significantly reduced iodine deficiency and associated health problems.

It is unlikely to get too much iodine from iodized salt alone if you adhere to recommended daily salt intake levels. However, excessive intake, especially from supplements or high seaweed consumption, can lead to thyroid problems.

No. Many processed foods use non-iodized salt, which is why relying solely on these products for your iodine intake is not recommended. It is best to use iodized salt for home cooking.