A 35-year-old woman from Bengaluru was shocked to learn that she had hypothyroidism after developing a large swelling in front of her neck (thyroid gland). Hypothyroidism is a condition where the thyroid gland does not produce the required amount of thyroid hormone.
Little did she know that switching to rock salt for years had led to iodine deficiency which became irreversible. Rock salt has very little iodine. It does not give the required amount of iodine for one’s body and using iodised salt is the only option, say experts.
Manju (name changed) reached the hospital only after her symptoms got worse. She was unaware that her diet lacked iodine rich food, until she was diagnosed with hypothyroidism. Iodine is an essential mineral required to make thyroid hormone that helps us control various functions in our body such as metabolism, muscle control and mood. Lack of iodine causes hypothyroidism while excessive iodine can lead to hyperthyroidism.
Tell-tale signs of iodine deficiency
Dr Shyam Sunder, Endocrinologist, Sparsh hospital, Bengaluru who treated Manju lists out a few signs and symptoms of iodine deficiency:
- Swelling of thyroid gland (visible lump called goiter)
- Sensitivity to cold
- Weight gain
- Depression
- Constipation
- Dry skin
- Muscle weakness
- Thinning of hair
- Weak nails
- Poor memory
Complications of iodine deficiency
“If hypothyroidism caused due to iodine deficiency is detected at an early stage, it can be treated and reversed. It is at the stage when the TSH (thyroid-stimulating hormone) levels are slightly increasing and there is slow enlargement of thyroid gland,” said Dr Sunder cautioning that once the thyroid gland is large and has multiple nodules in it, the condition becomes irreversible.
Dr Teena Mary Joy, Associate Professor, Department of Community Medicine, Amrita Hospital, Kochi said that iodine deficiency shows a spectrum of disorder. If someone is pregnant or lactating when they are deficient in iodine, it can affect the child’s growth. “It can lead to mental retardation and physical growth retardation which are irreversible and permanent. Studies have proven that children living in an iodine deficiency disorder endemic area have less IQ than those living in other areas,” she says. Intelligent quotient or IQ is the measure of a person’s reasoning ability.
Spectrum of iodine deficiency disorders, IDD.
Following is the spectrum of iodine deficiency disorders that affects a person in the different stages of their life.
| Fetus | Miscarriage
Stillbirths Congenital anomalies Increased perinatal morbidity and mortality Endemic cretinism |
| Neonate (new born) | Neonatal goiter
Neonatal hypothyroidism Endemic neurocognitive impairment Increased susceptibility of the thyroid gland to nuclear radiation |
| Child and adolescent | Goiter
(Subclinical) hypothyroidism Impaired mental function Retarded physical development Increased susceptibility of the thyroid gland to nuclear radiation |
| Adult | Goiter with its complications
Hypothyroidism Impaired mental function Spontaneous hyperthyroidism in the elderly Iodine-induced hyperthyroidism Increased susceptibility of the thyroid gland to nuclear radiation |
Source: NCBI, National Institutes of Health
Iodine requirement and its sources
Dr Joy says that one requires 150 micrograms of iodine per day. If a woman is pregnant or lactating the requirement is higher; between 220 – 250 micrograms. Some iodine sources are:
- Iodised salt
- Sea food/fish
- Egg
- Liver of any animal
- Seaweed
Iodised salt is the best option as one teaspoon contains 150 micrograms which is enough for daily requirement, says Dr Joy. She explains that iodine, available in the soil, is depleted due to changing agricultural practices and intensive use of fertilisers.
Iodised salt is easily available and consuming it every day will prevent its deficiency, says Dr Sunder. “Many people are choosing a diet with no salt or opting for rock salt, pink salt and other alternatives, resulting in iodine deficiency. Rock and pink salt have their own benefits and they are good to use but one must also include iodised salt in their diet,” he said.
Moderation is the key
Dr Sunder adds that consuming iodine rich foods such as seaweed in excess will be counterproductive as excessive iodine can be dangerous to one’s body. It may result in hyperthyroidism if their thyroid glands are not functioning normally.
He adds that using cruciferous vegetables such as cabbage and cauliflower excessively will result in hypothyroidism as these vegetables prevent the iodine uptake of the thyroid gland. These vegetables can be used in small portions everyday but excess use for different diets will cause harm.
Testing and treatment of iodine deficiency
Dr Sunder said that based on signs and symptoms the person exhibits, a physician might recommend them to get a urine test or a blood test to check the iodine levels. “If iodine deficiency is detected at an early stage, we recommend them to change their diet to include iodine rich food and put them on iodine supplements,” he said.
Recalling Manju’s case he said, “With the right treatment, her iodine levels improved. She underwent thyroxine replacement therapy which helped in normalising her TSH levels.”
Takeaways
- Long term iodine deficiency leads to hypothyroidism.
- Rock salt or pink salt have little or no iodine at all. Switching to iodised salt will help one get the required amount of iodine.
- If detected early, it can be reversed. If not, the condition will result in severe and permanent complications such as goiter, growth, mental and physical retardation.
- Using iodised salt on a regular basis will prevent its deficiency.
- Excess consumption of iodine could result in hyperthyroidism if thyroid function is abnormal.
