Optimal iodine nutrition intake

The monitoring program of iodine intake and thyroid diseases (DanThyr) was designed to secure optimal iodine nutrition of the Danish population, and also to improve knowledge on how to evaluate the iodine status of a population. Moreover, the design would give information on the epidemiology of thyroid disorders in areas with different levels of iodine intake, and the effects of an increase in iodine intake. An additional aim was to clarify the role of various environmental factors for the development of thyroid disease in the population, and in particular to study how these factors may interact with iodine intake. 

Delange et al. (Delange et al., 2002) determined the frequency distribution of urinary iodine in iodine-replete popnilations (schoolchildren and adults) and the proportion of concentrations <50 pg/1. The findings were as follows nineteen groups reported data from 48 popnilations with median urinary iodine concentrations >100 ig/l. The total population was 55 892, including 35 661 (64%) schoolchildren. Median urinary iodine concentrations were 111-540 (median 201) pg/1 for all populations, 100-199 ig/l in 23 (48%) populations and >/=200 jig/1 in 25 (52%). The frequencies of values <50 qg/1 were 0-20.8 (mean 4.8%) overall and 7.2% and 2.5% in populations with medians of 100-199 rg/l and >200 pg/1, respectively. The frequency reached 20% only in two places where iodine had been supplemented for <2 years. According to the authors conclusions the frequency of urinary iodine concentrations <50 Hg/1 in populations with median urinary iodine concentrations >/=100 rg/l has been overestimated, and the threshold of 100 qg/1 does not need to be increased. The main conclusion of the cited work was that in populations, median urinary iodine concentrations of 100-200 qg/1 indicate adequate iodine intake and optimal iodine nutrition. 

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