IODINE DEFICIENCY DISORDERS: 50 MILLION CHILDREN STILL EXPOSED
17 May 2002
In the year 2001 alone, 50 million children were born without any protection against iodine deficiency disorders during their fetal life, reports this month's Bulletin of the World Health Organization.
Mental retardation due to brain damage during fetal development is the most severe consequence of iodine deficiency, and it is caused by hypothyroidism resulting from iodine deficiency in the mother. The extreme result is cretinism, but much more common are the subtle degrees of mental impairment that lead to poor school performance, reduced mental ability and restricted capacity to work. Iodine-deficient communities have been found to score 10–15 points lower on IQ tests than iodine-replete ones.
"These disorders can be prevented by ensuring adequate iodine intake, which is the primary objective of the current worldwide drive to eliminate iodine deficiency disorders (IDD)," write WHO nutritionists Bruno de Benoist and Graeme Clugston.
That drive began in 1983, when a seminal paper by Basil Hetzel in the Lancet coined the term "iodine deficiency disorders", and made it clear that endemic goitre was only one of a wide range of conditions, to which the fetus was particularly exposed. The realization that adequate iodine intake was essential for normal brain development and lacking in so many children on such a global scale galvanized world opinion; action was seen as a political and moral imperative.
As Charles Todd, Health Adviser to the European Commission to Zimbabwe, writes in the current Bulletin's exchange of views on eliminating IDD: "The results have been very impressive, and even though the goal of elimination of IDD as a public health problem by 2000 has not been achieved in all countries, hundreds of millions of people who were at risk a decade ago no longer are."
In 1990 the elimination of IDD by the year 2000 was adopted as a goal by the World Summit for Children and the World Health Assembly. Since then, the number of countries with salt iodization programmes has risen from 46 to 93, iodized salt is now available in over two-thirds of the households in countries where IDD are endemic, and 20 countries have achieved universal salt iodization, defined as more than 90% of households having access to iodized salt.
The informal global partnership now taking the initiative forward includes WHO, UNICEF, the World Bank, three bilateral funding agencies, the International Council for Control of Iodine Deficiency Disorders (ICCIDD), the salt industry, and various nongovernmental and philanthropic organizations.
ICCIDD has become a key player along with WHO and UNICEF. It is a global network of scientists, epidemiologists and experts on public health and salt who work with governments at national level to set up and run salt iodization programmes. The Council now has 600 members from 100 countries.
Writing in this month's Bulletin, Basil Hetzel, ICCIDD's first Executive Director, sees sustainability as the primary challenge. In several countries, such as Colombia and Guatemala, early success has been followed by failure due to political and social upheavals. In countries of the former Soviet Union, where for many years iodine deficiency was seen as a problem of the past, IDD have returned for lack of vigilance.
Authors alone are responsible for views expressed in the Bulletin's signed articles, which are not necessarily those of the World Health Organization.