“On a worldwide basis, iodine deficiency is the single most important preventable cause of brain damage.” This statement is from the 2007 publication “Assessment of Iodine Deficiency Disorders and Monitoring their Elimination” by the United Nations Children's Fund (UNICEF), the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) and the World Health Organisation (WHO).
According to this publication, iodine deficiency is an easy and inexpensive nutrient disorder to prevent. However, the world is facing a major health problem; iodine intake levels are declining, even in countries such as the United States. Iodine deficiency affects one in three people worldwide; with two billion people having inadequate iodine intakes. With intake levels decreasing, iodine deficiency disorders may be increasing, affecting fetal development and the brain functioning at peak levels.
In areas of severe iodine deficiency people may have an intelligence quotient (IQ) of up to 13.5 points below those from an iodine-sufficient area, according to the UNICEF, ICCIDD and WHO 2007 publication.
Deficiency Affects More than Human Brain Function
Iodine is an essential trace mineral required for the production of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3).
The most common condition related to iodine deficiency and therefore a low thyroid hormone level is goiter or hypothyroidism. However, there is a range of conditions termed “iodine deficiency disorders”.
Iodine deficiency disorders include:
All ages:
- Goiter
- Hypothyroidism
- Increased susceptibility to nuclear radiation.
Fetal development:
- Spontaneous abortion
- Stillbirth
- Congenital anomalies
- Perinatal mortality.
Neonate:
- Endemic cretinism including mental deficiency with a mixture of mutism, spastic diplegia, squint, hypothyroidism, and short stature
- Infant mortality.
Child and adolescent development:
- Impaired brain function and therefore mental capacity
- Delayed physical development
- Iodine-induced hyperthyroidism.
Adults:
- Impaired brain function and therefore mental capacity
- Iodine-induced hyperthyroidism.
Low iodine levels affect fetal development and children the most. Iodine deficiency causing low thyroid hormone levels is the principal factor responsible for damaging the developing brain. The most critical period for iodine deficiency damage is from the second trimester of pregnancy to the third year after birth.
Communities that suffer from iodine deficiency have a poor quality of life, with little chance of achievement and a perpetuation of underdevelopment.
Low Iodine Intake is a Primary Factor in Deficiency
Low iodine intake is the primary cause of iodine deficiency disorders. A daily iodine intake of less than 20 micrograms per day will cause iodine deficiency symptoms to occur.
In order to overcome this major health problem countries have started iodized salt programs (as in the United States) or introduced iodized salt to breads (as in Australia). However, a recent study by Purnendu K. Dasgupta et al, “Iodine Nutrition: Iodine Content of Iodized Salt in the United States”, published in the 2008 Environmental Science & Technology journal, Volume 42, issue 4 revealed the levels of iodine in salt are below the United States Food and Drug Administration’s (USFDA) recommended iodine content.
Other causes of a low iodine intake and increased iodine deficiency risk include the reduced use of iodine in animal feeds and milk production, and an increased health awareness of a low salt diet.
Increased intake of iodine foods is necessary on an individual basis. This can become complicated with varying amounts found is soils. The oceans are a source of iodine so foods such as seaweed and fish are classed as iodine foods.
References:
Braun, L., & Cohen, M. (2005). Herbs & Natural Supplements- An evidence- based guide. Sydney: Elsevier Mosby.
de Benoist, B., McLean, E., Andersson, M., & Rogers, L. (2008). Iodine deficiency in 2007: global progress since 2003. Food Nutr Bull, 29(3), 195-202.
Eastman, C. (2005). Iodine Supplementation: The benefits for pregnant and lactating women in Australia and New Zealand. O & G, 7(1), 65-66.
Patrick, L. (2008). Iodine: deficiency and therapeutic considerations. Altern Med Rev, 13(2), 116-127.
Melissa Peterson - Melissa Peterson is a naturopath specializing in nutrition education. Melissa has been writing and editing technical and patient-friendly ...
Join the Conversation