Iodine Deficiency Disorders (IDD) is still prevalent in Indonesia. Since 1994 the Government of Indonesia launched iodized salt as the sole method to eliminate IDD. Unfortunately, many parts of the country, particularly in mountainous area could not achieve the target due to some reasons.The objective of the present study was to ascertain that iodine supplementation into drinking water can fill the gap. It was a school-based, long-term trial of iodine supplementation into drinking water in schoolchildren aged 8-10 years. That drinking water contained 200μg iodine/L. Four hundred and forty one children in Ngargoyoso sub-district were included in the study. Drop method of water iodization was used. Goiter was determined by palpation. The reduction of Total Goiter Rate (TGR) indicates effectiveness of the supplementation.TGRdecreased from 51.9% (2010) to 34.3% (2011) to 25.2 (2012) consecutively. No dropout wasreported. It seems thatsevere IDD endemic area with abundance of drinking water from spring well would benefit from the supplementation.

Although the relation of iodine deficiency to endemic goiter is well established, other factors may be involved. Some factors are related to food. The aim of the study was to prove that some foods locally grown in an iodine deficient area are goitrogenic. Twenty eight Wistar rats age 28 days, weight 60-70 g were randomly assigned into seven groups. The first group fed with AIN-93G as control group. Group II and III were given 25% and 50% raw soybean replacing the same weight of AIN-93G. Group IV and V were given 25% and 50% raw cassava replacing the same weight of AIN-93G. Group VI and VII were given 25% % and 50% raw cabbage replacing the same weight of AIN-93G. The length of the experiment was 34 days. The results showed that the control group fed with AIN-93G grew optimally, while the other groups showed deficits in growth significantly. Histological preparation of the thyroid gland were carried out under hematoxilyn eosin staining. Both 25% and 50% of raw soybean, raw cassava and raw cabbage produced colloid goiter. The study proved that foods locally grown in an iodine deficient area are goitrogenic.