ADEQUACY OF THE IODINE SUPPLY IN THE NETHERLANDS

Objective: To assess the adequacy of the iodine supply in the Netherla nds and to study possible ways of increasing the iodine intake. Design , settings and subjects: Goitre and nutrition surveillance studies (in take and urinary excretion of iodine) among population groups (age: 12 -85 y, n = 57-1704) in the Netherlands in the period 1981-1993. Simula tion studies, based on the Dutch Nutrition Food Consumption Surveys (n = 6000), calculating iodine intake among population groups after fict ively iodizing different food groups. Results: Mean intake of iodine, measured with different food consumption methods in the period 1984-19 93, met the recommended amount of 150-300 mu g per day in males, but n ot in females. Median urinary iodine excretion levels were in the rang e for mild Iodine Deficiency Disorders in both sexes. According to die tary methods reflecting habitual intake and urinary iodine excretion p er kg body weight or per mmol creatinin the prevalence of low iodine s upply among adults is between 4 and 20% for women and between 5 and 15 % for men. Iodization of different products would increase mean iodine intakes by up to 45% and would give a reduction of roughly 65% in the prevalence of low iodine intakes. Conclusion: The present goitre prop hylaxis in the Netherlands is not optimally effective. The iodine supp ly is below cut-off points in 4-20% of the adult population. It is pos sible to decrease the prevalence of low iodine intakes without a clear risk of exceeding the maximum acceptable daily iodine intake by incre asing the iodine content of baker's salt and/or by adding iodine to ot her foods.