Iodine Deficiency and Thyroid Dysfunction: Causes and Consequences

Iodine is an essential micronutrient for thyroid hormone synthesis (T₄, T₃).

Deficiency Effects

• Goiter: Thyroid enlargement from TSH stimulation.
• Hypothyroidism: Fatigue, weight gain, cold intolerance, constipation, dry skin, hair loss, cognitive slowing.
• Pregnancy: Cretinism (severe irreversible neurodevelopmental deficit), miscarriage, stillbirth.
• Children: Impaired growth, reduced IQ.

Sources & Prevention

• Iodized salt (primary public‑health strategy).
• Seafood, dairy, eggs, seaweed.
• RDI: 150 µg/day adults; 220 µg pregnancy; 290 µg lactation.

Universal salt iodization has dramatically reduced deficiency disorders globally.