What are the ingredients in Morton iodized salt?

January 1, 2026 •

3 min read

The addition of iodine to table salt was a major public health initiative in the 1920s to combat widespread iodine deficiency in the "goiter belt" region of the U.S.. This has led many to question what are the ingredients in Morton iodized salt, beyond just sodium chloride, and why these other compounds are included. The standard formulation of Morton's iodized salt includes sodium chloride, calcium silicate, dextrose, and potassium iodide.

Quick Summary

This article details the ingredients in Morton iodized salt: sodium chloride, calcium silicate, dextrose, and potassium iodide. It explains the function of each additive, from iodine supplementation to preventing clumping.

Key Points

Core Ingredients: The primary component is sodium chloride, which is table salt.
Iodine Source: The iodine is added in the form of potassium iodide to prevent deficiency.
Dextrose for Stability: A minute amount of dextrose, a sugar, is included to stabilize the potassium iodide and prevent it from evaporating.
Anti-Caking Agent: Calcium silicate is used to keep the salt crystals from clumping together in humid conditions.
Nutritional Benefit: The additions are for fortification and functional properties, providing essential nutrients and ensuring the product remains free-flowing.

The Core Ingredient: Sodium Chloride

At its heart, Morton iodized salt is predominantly sodium chloride, the chemical compound known as common table salt. This mineral is essential for human health, playing a crucial role in nerve function, muscle contraction, and maintaining the body's fluid balance. However, the pure form of sodium chloride is modified with additional components for specific functional and nutritional purposes.

The Role of Potassium Iodide

Since the 1920s, iodine has been intentionally added to salt to address a significant public health issue: iodine deficiency. The thyroid gland requires this essential micronutrient to produce hormones that regulate metabolism, growth, and development. In Morton iodized salt, this vital element is supplied in the form of potassium iodide.

Why Iodine Matters

Thyroid Health: Iodine prevents conditions like goiter, an enlargement of the thyroid gland, which was once common in iodine-deficient areas.
Cognitive Development: Adequate iodine intake is critical for proper brain and cognitive development, especially in pregnant women and young children.
Preventing Complications: During pregnancy, sufficient iodine can help prevent complications such as miscarriage and hypothyroidism in the mother.

Understanding Dextrose

Upon reading the ingredient list, some consumers are surprised to see dextrose, a simple sugar derived from corn. However, the amount is dietetically insignificant—Morton states it makes up just 0.04 percent of the salt. Its purpose is not for flavor, but as a stabilizing agent.

Dextrose as a Stabilizer

Potassium iodide can oxidize and evaporate over time when exposed to the air. Adding a small amount of dextrose helps prevent this chemical reaction, ensuring the iodine content remains stable throughout the product's shelf life. Other salts, particularly those sold outside the U.S., use the more stable potassium iodate and therefore may not contain dextrose.

Preventing Clumping with Calcium Silicate

Calcium silicate, a safe and common food additive, is included in Morton iodized salt as an anti-caking agent. Salt is naturally hygroscopic, meaning it absorbs moisture from the air, which can cause the crystals to clump together.

How Calcium Silicate Works

Absorption: The porous structure of calcium silicate allows it to absorb excess moisture.
Fluidity: It coats the salt crystals, reducing the friction between them and preventing them from sticking together, which keeps the salt free-flowing.

Comparison of Salt Types: Morton Iodized vs. Kosher Salt

To better understand the additives in Morton's iodized salt, it's helpful to compare it to a product like Morton's own kosher salt, which is often favored by chefs.


Feature	Morton Iodized Salt	Morton Kosher Salt	Notes
Ingredients	Sodium Chloride, Calcium Silicate, Dextrose, Potassium Iodide	Sodium Chloride, Yellow Prussiate of Soda	The non-iodized version has fewer additives. Yellow Prussiate of Soda is an anti-caking agent.
Crystal Size	Fine, uniform crystals	Large, flake-like crystals	The smaller, more dense crystals of iodized salt make it saltier by volume than kosher salt.
Iodine Content	Yes, fortified with iodine	No, not typically iodized	A key nutritional difference for those concerned with iodine intake.
Best For	Table use, measuring precisely in baking due to consistent crystal size	General cooking, finishing dishes due to its flaky texture and lower density	Many chefs prefer kosher salt for its texture and how it adheres to food.

Conclusion

What are the ingredients in Morton iodized salt? The full list includes sodium chloride, potassium iodide, dextrose, and calcium silicate. Each serves a specific purpose, from providing the essential mineral iodine to keeping the salt flowing freely. While some additives may seem unusual, they are present in very small amounts and are critical for the product's stability and public health benefits. While specialty salts like kosher or sea salt may contain fewer or different additives, Morton iodized salt remains a reliable and accessible source of iodine for most consumers.

Learn more about iodine's vital role in human health from the Office of Dietary Supplements at the National Institutes of Health(https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/).

Frequently Asked Questions

The primary ingredient in Morton iodized salt is sodium chloride, which is the chemical name for common table salt.

Dextrose is added to Morton iodized salt to act as a stabilizing agent for the potassium iodide, preventing it from oxidizing and evaporating over time.

Calcium silicate is an anti-caking agent. It is added to absorb moisture and prevent the salt crystals from sticking together, ensuring the salt remains free-flowing.

The amount of dextrose is very small and considered dietetically insignificant, making up only about 0.04 percent of the salt by weight.

Iodized salt is a specific type of table salt that has been fortified with iodine, typically in the form of potassium iodide, for nutritional purposes.

No, most salt used in processed foods is not iodized. This is why using iodized table salt at home is still important for ensuring adequate iodine intake.

Iodine was first added to salt as a public health measure in the 1920s to combat widespread iodine deficiency, which caused health problems such as goiter.