Your LCD TV screen was made with it; your brain does not function well without it. Meet iodine, a multifunctional chemical element found in soil and seawater that when mixed with table salt, is the most effective way to thwart preventable brain damage.
Consumed in too-small quantities by millions of children globally, iodine deficiency disorder (IDD) is one of the leading causes of mental retardation, say health experts.
But with few physical signs – save a swollen thyroid gland, or goitre – to herald its presence, IDD often debilitates quietly.
“With an infection, you have fever. But for micro-nutrient [deficiencies], the impact is hidden,” said Le Phong, coordinator of IDD activities at the government Hospital of Endocrinology in Vietnam’s capital, Hanoi.
Where nature has failed to produce adequate iodine, iodine-fortified table salt has been used widely – and successfully – in the past two decades to boost iodine intake in dozens of countries. In 1993, 110 countries were classified as “iodine-deficient”. Salt iodization brought that figure down to 32 in 2012, according to the Canada-headquartered International Council for the Control of Iodine Deficiency Disorders (ICC-IDD).
A number of countries, like Vietnam, eliminated IDD by outlawing non-iodized salt, regulating the salt industry, investing in health education to inform people about the link between salt and brain development, equipping laboratories and training technicians to measure iodine content in people and foods – only to see a resurgence in IDD when vigilance slipped.
Since declaring IDD under control in 2005, the country is once again facing falling iodine levels and rising complications, say health workers.
“We are losing a generation,” said Le from the Hospital of Endocrinology, referring to studies that link insufficient iodine intake during pregnancy to stillbirths, miscarriage, low birth weight, shortened child survival and mental retardation (irreversible even if the child is later exposed to sufficient quantities of iodine).
In 1993 two out of 10 schoolchildren surveyed in Vietnam had goitre and the median concentration of iodine in their urine (where iodine levels are measured) was only a fraction of leading health organization criteria for adequate iodine nutrition levels, which start at 100 micrograms per litre (mcg/l) daily for the general population, and go up to 250 mcg/l for pregnant and lactating women.
The surveyed schoolchildren averaged 32 mcg/l.
The following year the prime minister passed a decree calling for iodized salt in all food preparation; gave US$3.1 million to the Hospital of Endocrinology to manage the country’s battle against IDD; and set 2005 as the deadline to control IDD.
By 2005, the goitre rate fell to less than 4 percent, from 22 percent in 1993. Average iodine concentrations in schoolchildren 8-12 years old had almost tripled to 113 mcg/l in that period. Slightly more than nine out of 10 people surveyed nationwide reported getting enough iodized salt in their diet, a milestone known as universal salt iodization (USI).
But since then, funding to control IDD shrank to some $300,000 annually; a new decree was passed in 2006 that no longer made salt iodization mandatory; and the number of households using salt with sufficient iodine content has halved, according to a 2011 government survey that tested salt’s iodine content in more than 11,000 households nationwide.
Levels of iodine concentration among women of reproductive age (15-44) fell from 122 mcg/l in 2006 to 83 mcg/l in 2009. While pregnant women require higher levels of iodine than the general population, only 18 percent of them in Dong Thap, a southern province in Vietnam’s Mekong Delta region, had the iodine levels needed to give birth to healthy newborns, according to a 2008 government survey.
“Alarming”, concluded May 2012 research (not yet available on-line) by the World Health Organization (WHO), the UN Children’s Fund (UNICEF) and ICC-IDD, which analysed why a successful effort to control IDD slackened.
What went wrong?
The researchers concluded that downgrading IDD control from a national health priority to routine activities in the public health sector, with provincial authorities making decisions, “seriously affected” IDD control. Rather than giving iodized salt subsidies to communities most at risk of IDD living in mountainous areas, provincial officials gave cash (no conditions) to poor families to buy the salt for themselves. But rarely did that happen.
“With no adequate IEC [information, education and communication], it appears that most people use the money for other things instead of buying iodized salt,” the researchers found.
Starting in 2006, the central committee in control of IDD was dismantled with all responsibility given to the Hospital of Endocrinology, which Le, the director of the hospital’s IDD control activities, said is too overstretched to do much health promotion or education.
In a 2008-09 survey by his unit, 43 percent of mothers linked goitre to iodine deficiency, while only 19 percent knew lack of iodine could lead to mental retardation. Le said since 2006 when the national government stopped supporting the country’s 64 provincial labs set up to monitor salt iodine content, most are no longer operational. The only lab to receive government funding is Le’s.
Meanwhile, the global price of potassium iodate (KIO3), the form of iodine used to fortify salt, increased. A 2010 study of the global iodine market noted how a current global shortage of iodine, exacerbated by the 2010 twin disasters in Japan (a KIO3 producer), will keep prices unstable until up to late 2012. KIO3 prices nearly doubled between 2003 and 2011, reaching $60 per kilogram.
“We get less money for it and are getting less for our money,” said Le. Based on WHO’s recommendation of six grams of salt daily, Vietnam needs 187,000 tons of iodized salt annually. The Hospital of Endocrinology – currently the country’s sole purchaser of KIO3 – met 16 percent of that demand in 2011.
Boosting iodine levels can “theoretically be fairly fast, within months,” – as soon as iodized salt is sold – said Maria Andersson, a scientist with the Human Nutrition Laboratory at the Swiss Institute of Federal Technology and co-author of analyses about IDD trends over the past decade.
But the reality of how long it takes to reach the entire population with iodized salt depends on the effectiveness, knowledge and commitment of salt producers to iodize salt; whether laws require it; monitoring and control measures for iodine content; and the support the food industry has to include iodized salt in its products, she told IRIN.
For iodine nutrition to improve, the iodized salt needs to make it into households, and into their food – and most importantly – be consumed, said Andersson. It also needs to be well-packed so iodine is not lost during storage and transit.
It is also a question of how much time it takes to clear the shelves of non-iodized salt, which “won’t happen overnight”, said Roger Mathisen, a nutrition specialist at UNICEF’s office in Vietnam.
What to fortify?
In Vietnam, agencies and NGOs have looked to fortifying the widely-consumed fish sauce (made by fermenting fish with salt) with nutrients missing in diets.
Also popular is `bot canh’, a powder that includes salt, pepper and monosodium glutamate. In a 2010 survey of some 400 pregnant women in rural northern Vietnam (Ha Nam Province, 50km south of the capital), a quarter of the women reported not using iodized salt or cooking powders. Women said they felt iodized salt made food taste bitter and that monosodium glutamate or `bot canh’ made it taste “smoother”.
Salt iodization and fortification levels need to take account of the population’s iodine needs and how – and how much – people consume salt, Andersson added.
It is better to target salt, as most condiments already include it, said UNICEF’s Mathisen, who noted regulating the salt industry is easier than setting up parallel monitoring and enforcement systems.
With funding from the US Agency for International Development, UNICEF is advocating that the government revive salt iodization by making it mandatory once again, re-establishing national oversight, and shifting KIO3 procurement from the government’s budget to the salt industry’s so the consumer bears the cost, which is minimal said Le with the Hospital of Endocrinology. “We are talking about a price difference [between iodized and non-iodized salt] of 250 VND [one US cent] – less than the cost of a cigarette.”
Parliamentarians have agreed on the need to control IDD, but are reticent to tackle it again, he added. “It can be harder rebuilding something than it was to build it in the first place.”
But it is not just a question of building back, said Mathisen. “The issue is how to build back better. What existed was obviously not sustainable.”