URINARY IODINE EXCRETION AND INDIVIDUAL IODINE SUPPLEMENTATION AMONG ELDERLY SUBJECTS - A CROSS-SECTIONAL INVESTIGATION IN THE COMMUNE OF RANDERS, DENMARK

Several studies have demonstrated that the iodine intake is relatively low in Denmark. However, the results are difficult to interpret becau se no information has been given on the frequency of individual iodine supplementation. We performed a cross-sectional study of elderly subj ects living in the commune of Randers, Denmark. Urinary iodine excreti on was measured in the 423 participants (185 males, 238 females) and a careful history was taken on any possible intake of supplementary iod ine. The median urinary iodine excretion was 48.3 mu g/g creatinine fo r the whole population (40.8 mu g/g creatinine in males, 53.2 mu g/g c reatinine in females). In the part of the population that did not take iodine supplementation (46.7%) the median value was 36.1 mu g/g creat inine (males 33.8; females 38.8). Regular iodine supplementation taken as an iodine-containing vitamin/mineral tablet was found in 30.8% of the population. This increased the urinary iodine excretion to a media n level of 80.5 mu g/g creatinine (males 62.0; females 88.0). The stud y shows that the basic iodine intake level is overestimated if individ ual iodine supplementation is not taken into account. Such supplementa tion may lead to median iodine excretion values that seem reasonable, even if the iodine intake of the part of the population not taking iod ine (in this study, nearly half of the population) is low.