What is Iodine and Why Do We Need It?
Iodine is a trace element that our bodies cannot make, meaning we must get it from our diet. Its most critical job is to help the thyroid gland, a small butterfly-shaped organ in the neck, produce thyroid hormones. These hormones, thyroxine (T4) and triiodothyronine
(T3), act like the body's master regulators. They control our metabolism—the speed at which our body converts food into energy—and are essential for growth, body temperature regulation, and the proper function of our organs, including the brain, heart, and muscles.
Signs You Might Be Running Low
When iodine levels fall, the thyroid gland can't produce enough hormones, a condition known as hypothyroidism. One of the most visible signs is a goitre, which is a swelling of the thyroid gland in the neck as it works overtime to capture any available iodine. Other common symptoms are often subtle and can be mistaken for general fatigue. These include unexplained weight gain, constant tiredness, sensitivity to cold, dry and scaly skin, thinning hair, a hoarse voice, and even confusion or impaired mental function.
Impact on Brain Development and Pregnancy
Adequate iodine is most critical during pregnancy and for infants. A deficiency in the mother can lead to severe consequences for the baby, including stunted growth, intellectual disabilities, and developmental delays. Iodine is the building block for fetal brain development, and a lack of it is considered the world's single largest cause of preventable brain damage. Studies have shown that children born in iodine-deficient areas can have significantly lower IQ points than those from iodine-sufficient regions. For this reason, pregnant and breastfeeding women have higher daily iodine requirements.
India's Success with Iodized Salt
Recognizing the widespread risk due to iodine-poor soil across the subcontinent, the Government of India launched the National Goitre Control Programme in 1962, which was later renamed the National Iodine Deficiency Disorders Control Programme (NIDDCP). The core strategy has been the universal iodization of salt, a simple and effective way to ensure the entire population gets enough of this vital nutrient. This public health initiative is considered a major success, with over 90% of Indian households now consuming iodized salt, dramatically reducing the prevalence of goitre and other related disorders.
How to Ensure You're Getting Enough
For most people in India, using iodized salt is sufficient. The recommended daily intake for adults is about 150 micrograms (mcg). Beyond iodized salt, good dietary sources include dairy products like milk and curd, eggs, and seafood such as marine fish and shrimp. While some vegetables like spinach contain iodine, the amount can vary based on the soil they are grown in. For most people eating a balanced diet, deficiency is unlikely, but those on strict vegan diets who avoid fish and dairy may need to be more mindful of their intake.
Can You Have Too Much Iodine?
While deficiency is a concern, it is also possible to have too much iodine, though this is rare from food alone. Excessive intake, usually from high-dose supplements, can also disrupt thyroid function, sometimes causing hyperthyroidism (overactive thyroid) or, paradoxically, hypothyroidism. Symptoms of excess iodine can include a burning sensation in the mouth, nausea, and vomiting. The upper safe limit for adults is 1,100 mcg per day. It is best not to take iodine supplements unless specifically advised by a doctor.
