Endocrinologist shares hidden link between iodine, thyroid and your mood that many people ignore

There's a hidden link between iodine, thyroid and your mood (Picture Credit: Pexels)

Iodine, a trace mineral remains vital for thyroid health and wellbeing. Subtle fatigue, weight gain, or mood swings often turn out to be symptoms of a mild iodine deficiency, hidden behind fast food, non-iodised salts, and urban stress.

Despite India’s success with salt iodisation, deficiency hasn’t vanished. In fact, the changing diets may have invited it back. “I see patients who rarely touch traditional iodised salt,” says Dr Abhijit Bhograj, Consultant Endocrinologist, Diabetes and Thyroid Specialist, Manipal Hospital, Hebbal, Bengaluru. “Many rely on processed foods, and most commercial snacks use non-iodised salt. Over time, this can create a mild but significant deficiency," he added.

People living in hilly or rain-washed regions, where soil iodine is low, are especially at risk, he says, adding, “And because symptoms develop gradually, they often blend into the background of everyday life mistaken for tiredness, stress, or ageing.”

Dr Bhograj shares silent signs that you should watch out for:

Persistent fatigue – Feeling drained even after good rest.
Gradual weight gain – Despite normal eating habits.
Cold intolerance – Hands and feet that are always icy.
Dry skin and hair thinning – A dull complexion and brittle hair.
Neck swelling (goitre) – A tell-tale enlargement in the throat area.
Brain fog and mood swings – Forgetfulness, anxiety, or low motivation.

“These signs can appear even before blood tests pick up thyroid changes,” Dr Bhograj explains. “That’s why awareness is so crucial.”

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Iodine is one of those nutrients where balance is everything. Too little slows down the thyroid; too much can tip it into overdrive. “Self-prescribing iodine supplements is risky,” warns Dr Bhograj. “Excess iodine can actually trigger thyroid dysfunction in some people. It’s always best to test before treating.” He stresses that supplementation should be medically guided — not based on online advice or guesswork.

Other nutrients that help your thyroid
Your thyroid relies on nutrients that help hormones function smoothly:
Selenium – Protects the thyroid from oxidative stress.
Zinc – Regulates the conversion of thyroid hormones.
Iron – Needed to convert T4 into active T3.
Vitamin D – Balances immune function and supports thyroid health.Vitamin B12 – Maintains energy and nerve health, often low in hypothyroid patients.

“Deficiency in any of these can worsen thyroid issues,” notes Dr Bhograj. “So, instead of focusing on one nutrient, aim for overall balance.”
If you’ve noticed unexplained tiredness, weight gain, mood changes, or swelling around your neck, it’s time to get checked.

Your doctor may recommend:
Thyroid function tests (TSH, Free T3, Free T4) – To assess hormone levels.
Thyroid antibodies – To rule out autoimmune thyroid disorders.
Urinary iodine – Occasionally used to measure iodine intake directly.

“These tests lend a full picture,” says Dr Bhograj. “Once we know what’s missing, it’s easy to correct with diet or medical guidance.”

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1. How does iodine affect my thyroid function?

Iodine is an essential mineral your thyroid needs to produce hormones like thyroxine (T4) and triiodothyronine (T3). Without enough iodine, your thyroid can’t make these hormones properly, leading to hypothyroidism — a condition that can affect your metabolism, energy, and mood.

2. Can low iodine levels really impact my mood or mental health?

Yes. When iodine is low, thyroid hormone production drops, slowing brain function. This can lead to symptoms like fatigue, depression, poor concentration, and low motivation. Studies have shown that correcting iodine deficiency often helps improve mood and mental clarity.

3. What happens if I have too much iodine?

While iodine deficiency is a problem, excess iodine can also disrupt thyroid function — sometimes triggering hyperthyroidism or autoimmune thyroid issues. This imbalance can cause anxiety, restlessness, or irritability, showing that both too little and too much iodine can affect mood.

4. How can I tell if my mood changes are linked to my thyroid?

If you experience unexplained mood swings, fatigue, or cognitive fog along with physical symptoms like weight changes, dry skin, or feeling unusually cold or hot, it’s worth checking your thyroid function with a blood test (TSH, T3, and T4 levels).

5. What are good dietary sources of iodine for healthy mood and thyroid balance?

Natural sources include seaweed, fish, dairy products, and iodized salt. A balanced intake supports optimal thyroid hormone production — and by extension, a more stable mood and energy level.

Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for a specific health diagnosis