Iodine Is Essential!

Iodine: The Tiny Element That Keeps Your Body Running Smoothly

You’ve probably seen the little “I” on nutrition labels and wondered what it does. The answer is a lot. Iodine is an essential micronutrient—your body can’t make it, so you have to get it from food or supplements. Without enough, your thyroid (the butterfly-shaped gland in your neck) can’t produce the hormones that control metabolism, growth, brain development, and basically every cell in your body.

Yet despite its superstar status, iodine often gets a bad rap. Some people avoid iodized salt or seafood out of fear of “iodine allergy” (spoiler: true iodine allergy does not exist—read our debunk here). Let’s set the record straight and show why this element deserves a spot on your plate.

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Why Your Body Needs Iodine

1. Thyroid Hormone Production
   The thyroid uses iodine to make thyroxine (T4) and triiodothyronine (T3). These hormones regulate:
   • Basal metabolic rate (how many calories you burn at rest)
   • Heart rate and body temperature
   • Brain development in fetuses and infants
2. Cognitive Function & Mood
   Iodine deficiency during pregnancy is the leading preventable cause of intellectual disability worldwide (WHO, 2023). Even mild shortfalls in adults can cause brain fog, fatigue, and depression-like symptoms.
3. Reproductive Health
   Adequate iodine supports ovulation, sperm production, and healthy placental function.
4. Immune & Detox Support
   Iodine has mild antimicrobial properties and helps the body excrete heavy metals like mercury and lead.

How Much Do You Need?

Life Stage	RDA (μg/day)
Adults	150
Pregnancy	220
Lactation	290
Infants 0–6 mo	110 (AI)
Children 1–8 yr	90

Source: National Institutes of Health, 2024

A single gram of iodized salt contains ~45 μg of iodine—about one-third of an adult’s daily need. Seaweed, seafood, dairy, and eggs are other top sources.

Signs You Might Be Low

• Unexplained weight gain
• Constant fatigue
• Dry skin, hair loss, brittle nails
• Feeling cold all the time
• Goiter (swelling in the neck)
• Brain fog or poor memory

Note: These overlap with dozens of conditions. If you suspect deficiency, ask your doctor for a urinary iodine concentration test—it’s the gold standard.

The Iodine Allergy Myth

True allergy to elemental iodine does not exist. What people usually react to are:

• Iodinated contrast dyes used in CT scans (reactions to the entire molecule, not the iodine)
• Povidone-iodine (Betadine) antiseptic (irritation from the povidone carrier)
• Shellfish proteins (often misattributed to iodine)

Bottom line: You can safely eat shrimp, seaweed, or iodized salt unless you have a documented reaction to one of the above.
Read our full myth-busting post on “iodine allergy” here.

Smart Ways to Get Enough Iodine

1. Use iodized salt in cooking (store in an opaque container to prevent iodine evaporation).
2. Eat seaweed snacks—nori, kelp, or dulse (just 1–2 g covers your daily need).
3. Include seafood 1–2×/week (cod, tuna, shrimp).
4. Choose dairy—milk and yogurt are major iodine sources in many countries.
5. Consider a supplement only if your diet is low (e.g., vegan + no iodized salt). Look for potassium iodide or kelp tablets and stick to 150–225 μg/day.

Caution: More is not better. Chronic intakes >1,100 μg/day can trigger thyroid dysfunction in susceptible people.

The Global Impact of Iodine Deficiency

• 2 billion people worldwide have insufficient iodine intake (WHO, 2023).
• 29 countries still have widespread deficiency.
• Universal salt iodization has reduced cretinism (severe iodine-deficiency disorder) by 70% since 1990.

One simple policy—adding iodine to table salt—has prevented millions of cases of intellectual disability. That’s nutritional public health at its finest.

Takeaway

Iodine isn’t scary—it’s essential. A pinch of iodized salt, a sheet of nori, or a serving of cod can meet your needs without drama. Focus on whole-food sources, get tested if you’re worried, and ignore the allergy myths.

Still worried about “iodine allergy”?
👉 Read our companion post: “I’m Allergic to Iodine—Or Am I?”

Have questions about iodine or thyroid health? Drop them in the comments—we read every one.