To evaluate the iodine nutritional status of children living on the island of Tanna, Republic of Vanuatu.

Cross-sectional study. Urine and household salt samples were collected for iodine measurement. Thyroid volumes were measured by ultrasound. A food consumption frequency survey was carried out, particularly in relation to salt, iodine-rich foods and foods that containing thiocyanate, a potentially goitrogenic substance. Urinary thiocyanate levels were also measured.

Island rural communities in Tanna, Vanuatu.

One hundred and fifty-three schoolchildren between 8 and 10 years of age from four locations on the island participated.

The median urinary iodine excretion (UIE) among the children was 49mg/l, indicating moderate iodine deficiency. This was corroborated by 27% of boys and 33% of girls having thyroid glands greater than the international standard for their age, and 36% of boys and 45% of girls having thyroid glands greater than the international standard for their body surface area based on ultrasonography. There was a highly statistically significant inverse correlation between thyroid volume and UIE for boys and girls (r = −0·444, P = 0·001 and r = −0·319, P = 0·005, respectively). There was no correlation between thiocyanate and UIE or thyroid volume. Only 34% of children reported to consume fish (tinned or fresh) on a weekly basis.

Against the common perception, the study has demonstrated that the children on the island of Tanna were in a state of moderate iodine deficiency. More data need to be collected from other Pacific Island countries in order to provide evidence for formulating public policy in prevention and control of iodine deficiency disorders in these nations.