Iodine Deficiency disorders


Iodine Deficiency disorders (IDD) are a wide spectrum of deficiencies resulting from the lack of iodine in the diet. Iodine deficiency leads to a reduction of intellectual disabilities and physical capacity and may manifest as goitre, mental retardation, physical and mental defects, and cretinism.

Iodine is an essential micronutrient and is obtained from the food that we intake. Iodine is required by our body for thyroid hormone (triiodothyronine and thyroxine) production by the thyroid gland. Iodine deficiency is prevalent and a significant public health concern. World Iodine deficiency Day on October 21 is to raise awareness about the importance of iodine and its deficiency and aims on working towards the prevention of the disorders.

The iodine required by our body differs according to physiological changes. Low iodine levels cause several poor health outcomes, like thyroid abnormalities (goitre or hypothyroidism), impaired cognitive abnormalities, neuromuscular weakness, congenital abnormalities, stillbirth, or spontaneous abnormalities. 

Iodine deficiency at critical stages during pregnancy and early childhood results in impaired development of the brain and consequently, impaired mental function.

 

Facts to know:

  • More than 70% of the world's population is iodine deficient.
  • Women in pregnancy need 150 µg of iodine daily 

Average recommendation of Iodine daily depending on age-

 

 

Life stage  Recommended amounts of Iodine
Birth to 6 months 110 mcg
Infants  130 mcg
Children of 1-8 years 90 mcg
Children of 9-13 years 120 mcg
Teenagers (14-18 years)  150 mcg
Adults  150 mcg
Pregnant or breast feeding women 220-290 mcg

 

Food Sources of Iodine:

  • Iodized salt
  • Fruits and vegetables
  • Dairy products (milk, cheese, yogurt, etc)
  • Grains like bread and cereals
  • Fish like Tuna, Shrimp, Tuna and other seafoods

Iodine function in human body

  • Iodine plays a major role as an important part of thyroid hormone production that regulates cell metabolism and other functions of the brain and bone development during the pregnancy and in infancy.
  • Improves cognitive function during childhood. Severe iodine deficiency during childhood can lead to harmful effects on the development of the brain and nervous system. Iodine supplements can help children improve their physical development, reasoning ability, and overall cognitive function.
  • Prevents fibrocystic breast disease affects women of reproductive age and sometimes can occur even during menopause causing painful and lumpy breasts. Iodine supplements taken in high doses can reduce pain and other symptoms. However, consulting a physician before taking the supplementation is necessary.
  • Reduces radiation-induced thyroid cancer risk. Individuals with iodine deficiency, when exposed to radioactive iodine, are at a higher risk of developing thyroid cancer. The U.S. Food and Drug Administration (USFDA) approved potassium iodide as a thyroid-blocking agent, which aids in reducing the risk of thyroid cancer in radiation emergencies.

Expected levels of Iodine:

  • Median urinary Iodine levels in any target population must be 100 µg/I and not more than 20% of values are below 50 µg/I.
  • At least 90% of households are using salt with an iodine content of 15 ppm (parts per million) or more
  • There is evidence of sustainability, as judged by the attainment of at least eight out of ten specified programmatic indicators.

The spectrum of Iodine Deficiency Disorders (IDD): 

 

FETUS

Abortions
Stillbirths
Congenital anomalies
Increased perinatal mortality
Increased infant mortality
Neurological cretinism 
Mental deficiency; Deaf mutism
Spastic diplegia squint
Myxoedematous cretinism
Mental deficiency, dwarfism, Hypothyroidism
Psychomotor defects

Neonate Neonatal hypothyroidism

Child & Adolescent

Retarded mental and physical development
Adult Goiter and its complications Iodine-induced hyperthyroidism (IIH)

All ages

Goitre 

Hypothyroidism

Impaired mental function Increased susceptibility to nuclear radiation

 

People living in areas affected with severe IDD may have an intelligence quotient (IQ) of about 13.5 points below those of comparable communities (where there is no Iodine deficiency). Mental deficiency has an immediate effect on children’s learning capacity, women’s health, the quality of life of communities, and economic productivity.

Deficiency during childhood causes reduced somatic growth and cognitive and motor function.

The most critical period is from the second trimester of pregnancy to the third year after birth. In areas of iodine deficiency, where thyroid hormone levels are low, brain development is impaired.

In its most extreme form, this results in cretinism, but of much greater public health importance are the more subtle degrees of brain damage and reduced cognitive capacity which affect the entire population. As a result, the mental ability of ostensibly normal children and adults living in areas of iodine deficiency is reduced compared to what it would otherwise be

Assessment methods:

  1. Urinary Iodine concentration
  2. Presence of goitre
  3. Newborn TSH (thyroid stimulating hormone) concentration
  4. Serum thyroglobulin concentration

Low levels of thyroid hormone or high levels of thyroid-stimulating hormone (TSH) can indicate iodine deficiency. Luckily, deficiency is easy to prevent. Mapmygenome’s comprehensive health screening blood tests that include thyroid profile is a way of identifying iodine deficiency. If caught early, iodine deficiency can be reversed with little or no side effects.