Friday, 12 October 2012

Iodine Nutrition of Humans

Situation  the UK.

It has been established around the world that severe iodine deficiency during pregnancy can cause irreversible brain damage in the foetus. It is important that Iodine intakes are sufficient during pregnancy; it is thus a serious matter for women of reproductive age.

It was disappointing enough to learn in 2011 from a small survey that 2/3 schoolgirls in the UK were iodine deficient but I am shocked by the finding, reported in early 2012, that of 193 countries worldwide the UK is one of the 10 worst iodine deficient countries that have the most school age children with insufficient iodine intake.

These findings are those of the International Council for Control of Iodine Deficiency Disorders who over the last 40 years has been instrumental in helping third world countries combat iodine deficiency with salt iodisation programs. I have followed their successes across the part of my activities with my Micronutrient Bureau since 1980.

It is sad to realise that the UK is now a “third world country” with regard to iodine.

The World Health Organisation recommendations (2007) are:
250 micrograms of iodine per day for pregnant women,
150 micrograms for adults,
120 micrograms for children 5-13 years and
90 micrograms for children under 5 years.
These iodine intakes can be achieved by including iodine-rich food in the diet, such as sea fish and sea foods but these are seldom eaten regularly.
The higher iodine requirement in pregnancy and lactation may necessitate the taking of supplements. Women may consider taking a daily pregnancy supplement, typically containing about 150 micrograms iodine.  It is important that kelp or seaweed supplements are not used as iodine sources as these products have very variable, and often extremely high, concentrations of iodine that could lead to problems caused by excessive intake.

Most of the iodine in the typical UK diet comes from milk and dairy products. This is the result of the inclusion of iodine in animal feed (mostly fed indoors and not used by organic farmers) and from the contamination of dairy equipment with the iodophors used as disinfectants.

Iodine concentrations in milk vary with summer milk containing less iodine than winter milk. Organic milk contains up to 40% less iodine than conventional milk.

Two glasses of conventional milk, 1 egg, cereals and bread and butter is a good start, which together with the iodine in meat, vegetables, fruit and beverages (possibly totaling up to 100 micrograms) may be sufficient.

It is advisable that iodine nutrition in pregnancy is discussed with the GP and health adviser.

Iodine deficiency and sufficiency can be easily assessed by urine analysis and can be readily prevented and corrected by eating sufficient iodine-rich food. At the very least the message that iodine is required for brain development needs to be got across to all planning a family.

It is hoped that one day a nation-wide survey of the iodine situation will be carried out in the UK by urine analysis. At present the nutritional adequacy of the national diet is assessed by analysis of food combined with quantities of food consumed by different groups of people. It is accepted that young women in the UK are unlikely to get sufficient iodine because their diets are inadequate but this does not seem to have led to any advice regarding iodine in pregnancy.    

October 2012

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