Iodine deficiency, as the name suggests, is a lack of iodine — a micronutrient used by the body to produce thyroid hormones (thyroxine, triiodothyronine), which are necessary for normal growth, development and metabolism throughout life. Lack of iodine in diet is called Iodine Deficiency Disease (IDD).

The body does not produce iodine, thus iodine intake is an essential part of our diet. Iodine is found in various foods (see Table 1). If we do not have enough iodine in our body, we cannot produce enough thyroid hormone. Thus, iodine deficiency can lead to enlargement of the thyroid (goiter), hypothyroidism and to mental retardation in infants and children whose mothers were iodine deficient during pregnancy.

Table 1

Iodine deficiency is the world’s most prevalent, yet easily preventable, cause of brain damage. A billion people-roughly 15% of the world population suffer from iodine deficiency disorder (IDD).

The World Health Organization (WHO) defines optimal iodine intake-measured as median urinary iodine (UI) concentration as 100 – 199 ?g/L.

National Study Control and Prevention of Iodine Deficiency Disorders (IDD)(1995) conducted among school children aged between 8-10 years in the country found that the prevalence of goiter among school children in Peninsular Malaysia is 2.2% while Sabah was 17.9% and in Sarawak is 0.4%. However, there are some states in Peninsular Malaysia which goiter prevalence exceeds 5% and this has led to the decision to implement the Program for Prevention and Control of Iodine Deficiency Disorders (IDD) as a whole in countries that have been identified problematic.

In addition, a variety of strategies and activities have been designed and implemented to address the problem of IDD in Peninsular Malaysia. This includes the distribution of iodised salt to pregnant women and children malnutrition in certain areas of Perlis and Kedah, Perak, Pahang, Terengganu and Kelantan. In addition, nutrition education and counselling on health given to improve their nutritional status has also helped to the eradication of this problem.

Measurement of urinary iodine is the most commonly used method for assessing iodine sufficiency’s in a population. Because more than 90% of dietary iodine is excreted in the urine, UI concentrations directly reflect the level of iodine intake.

Laboratory methodologies frequently used to measure urine iodine levels are the Standard Spectrophotometric Methods and the Inductively Coupled Plasma–Mass Spectrometry (ICP-MS).