Thursday, May 28, 2009

Prevention of iodine deficiency should be priority

Iodine supplementation is probably the cheapest and most effect way to increase the human capital -- indeed, the wealth -- of a nation. Yet, this simple, clear-cut intervention -- one that addresses the entire range of social and economic problems in one swoop -- seldom seems to top the agenda of national policy makers or international development banks and agencies.

Thailand is known for having been one of the first developing countries to make serious progress in addressing iodine deficiency -- a syndrome that can lead to mental retardation or intellectual impairment.

Like many parts of the world, the soil in Thailand is deficient in iodine, so the only way to ensure children get sufficient quantities of this mineral -- allowing for the full development of their brains -- is through dietary supplementation.

In the West, this is achieved through adding iodine to salt.

However, in Thailand only two-thirds of cooking salt contains iodine. Also, Thai cooking may present added challenges because in many villages not salt but fish sauce tends to be the seasoning of choice. Efforts have been made to get "fish sauce" makers to add iodine. Sources inform me that the fish sauce industry has balked at this idea in the past, claiming iodine will "change the taste" of the sauce.

If you look at a map published in 2001 (coming soon), you see Thailand appears to have been relatively successful in its efforts to provide iodine to the population. But a more recent map (above) shows Thailand lagging behind other ASEAN countries. A 2003 WHO report singled out Thailand and Bhutan as model countries that had "virtually eliminated IDD," noting further that 79% of Thai households consume iodized salt and that Goitre prevalence in Thailand had decreased from 19% in 1989 to 2% in 2001. In 1997, the government even declared a "National Iodized Salt Day."

Were such accolades with respect to Thailand premature? Would the enthusiasm for making rapid progress on the issue dissipate?

It would seem so. More recent figures suggest that Thailand stumbled, failing to sustain its earlier progress.

Although Thailand was the first country in the region to make progress against iodine deficiency, of all countries in ASEAN, Thailand has made the least progress in recent years. This point is illustrated by the adjacent chart by Prof. C Eastman of the University of Sydney. His chart shows that from the mid 1990s to the mid 2000s -- a time when all other ASEAN countries were consuming vastly more iodized salt -- Thailand not only failed to match this progress, it would find itself lagging behind poor neighboring countries like Laos and Myanmar!

A 2006 study described the urgent "need for multimicronutrient interventions in North East Thailand." The study of schoolchildren reported that 83% had low urinary iodine levels. A glace at the map at the ICCIDD website (re-posted above) shows Thailand lagging well in behind other countries in the region in treating iodine deficiency.

The problem concerning iodine deficiency in Thailand mainly concerns "the Northern and North-eastern regions where soil does not contain iodine and villagers do not regularly eat seafood" according to a 2006 ICCIDD newsletter. It must be asked whether governments of the post 2006 coup era -- several of which have been under-represented by representatives from the Northern and North-eastern regions -- have shown adequate commitment to addressing this critical problem facing these residents.

Other ways to address the problem of iodine deficiency:
  • A few weeks ago I blogged about a project called Cola Life. Perhaps iodine deficiency is something that that soft drink manufacturers could help to address.
  • School lunch programs could be another means of delivering iodine to children in Thailand according to a recent study.
  • A 2001 study found that a low-cost solution to the iodine deficiency in Thailand might be water iodization.


  1. I found this statement at the end of the water iodization summary to be interesting: "However, the need for behavioral modification raises the issue of long term sustainability." Like the condoms in the Cola Life packet, this stuff is only going to be useful if the consumer deems it to be so. Jotman, do you know of any plans in Thailand to support this with a media campaign?

  2. J-P,

    Surely the solution, long-term, to iodine deficiency anywhere is to find a way to do it that does not require any change in behavior on the part of consumers. Also cheapest, because marketing, which you mention, makes behavior change an expensive approach.

    I mentioned cola, but mainly as a way to encourage thinking about approaches.

    Far better to add iodine universally to something people already universally consume, like salt. Though in Thailand, due to cooking habits, it seems as if that's not going to cover everyone.

  3. Just curious, what potential does iodizing (sp?) tap water have? Where I live, and probably beyond, the water is fluoridated as a means of promoting good dental health. Does Thailand have enough running water to make this work? If not, do you think that investing in water delivery systems might solve a couple of problems with one stroke?

  4. J-P,

    As I recall, one of the studies mentioned in the post looks at the question of iodizing tap water, and found it cost-effective relative to some other means.

    I think a far better case can be made for adding iodine than fluoride to drinking water (for one thing, iodine is an essential element in diet, but fluoride is not).

    Speaking of fluoride, I think there is good reason to oppose the practice of adding fluoride to drinking water -- I hope Thailand never goes down that road.

    I blog about fluoride here:

  5. AnonymousJuly 20, 2015

    I have been trying to purchase iodine in an oral form but have not been able to find it in Bangkok. Moreover, none of the pharmacists and more than a few doctors did not know what it is. This is most strange. Does anyone know of a source?


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