Median urinary iodine excretion

In a substudy of MoBa, including pregnant women grouped as users or nonusers of vitamin and mineral supplements, median urinary iodine excretion per 24 h was 190p,g and 110p,g, respectively (Brantsaeter et al., 2007). In the same study, dietary iodine intake was calculated by a food-frequency questionnaire and a food diary. The dietary intake of iodine among nonsupplement users was below the recommendations, whereas the dietary iodine intake of supplement users was above the recommendations. This demonstrates that supplements may contribute considerably to the total dietary iodine intake. 

In a follow-up study, 3761 randomly selected subjects, above 13 years, living in one of three regions in China with mild ID (median urinary iodine excretion 84p,g/l), more than adequate iodine intake (urinary iodine 243pg/l), and excessive iodine intake (urinary iodine 651 p.g/1) were included (Teng et ai, 2006). At baseline, the prevalence rates of high level of TPO-Ab (TPO-Ab > 50 lU/ml)... 

Figure 119.3 Geographical variations in urinary iodine excretion in Denmark before iodine fortification of salt. Median urinary iodine excretion among inhabitants of various Danish cities before iodine fortification of salt, and the estimated number of people living in areas with different levels of urinary iodine excretion. Values were compiled from different studies of urinary iodine excretion, or estimated from measurements of groundwater iodine content. Geographical variation in iodine intake in Denmark is mostly determined by differences in groundwater iodine content. Pedersen etal., (1999) Rasmussen etal., (2000).

Areas Neonatal TSH 97% cut-off (nU/nnl) Goiter prevalence (%>) Median urinary iodine excretion (pg/i)... 

The iodine intake in this area was optimal, as judged by the median urinary iodine excretion of 183 p.g/1. 

Figure 125.3 The relationship between urinary iodine levels and the prevalence of overt hyperthyroidism in GD family members. MUI median urinary iodine excretion GD, Graves disease 234 family members urinary samples were taken and 69 of them were diagnosed with overt hyperthyroidism. The incidence of overt hyperthyroidism in groups with urinary iodine between 500 and 599 (ig/l were significantly higher than those with urinary iodine 100 99(jg/l (P < 0.05).

More than 600 ag/i Median Urinary Iodine Excretion Might be Connected to Eievated Incidence of Papillary Thyroid Carcinoma... 

These studies were somewhat hampered by the lack of knowledge on the frequency of individual iodine supplementation in the form of daily intake of iodine containing vitamin/mineral tablets. Such tablets are commonly employed in Denmark and many brands contain 150 Mg iodine. For a correct interpretation of the results it is necessary to know whether a person participating in a survey takes such tablets. Normally the iodine intake in an area is considered sufficient if the median urinary iodine excretion exceeds a certain value. If a substantial proportion of the population is taking regular iodine supplementation, this may lead to a median excretion vjdue well about what is considered a critical level, and still leave the part of the population which is not taking iodine at risk. 

We performed a cross sectional study in the commune of Randers, East Jutland. All subjects bom in 1920 were invited to participate, and 423 (63%) participated. A careful history was taken on the intake of vitamin/mineral tablets and other possible sources of supplementary iodine. In 51.5% of the subjects no evidence of extra iodine intake was obtained. These subjects had a median urinary iodine excretion of 36 Mg/g creatinine in a morning spot urine. In Denmark the daily creatinine excretion in urine is in the order of 1 g in this age group. Regular iodine supplementation in the form of daily intake of iodine containing vitamin/mineral tablets was taken by approximately one third of the population while many took various health products of unknown composition. 

The median urinary iodine excretions varied between 12 and 129 /ig I/g creat. in the different areas. In 61/178 areas, the median iodine excretion was equal to or below 50 ixg I/g creat. The median urinary iodine in schoolchildren in Lisbon was 71 /ug I/g creat. An updated (1991, first trimester) study of the urinary iodine excretion by the adult population in Lisbon is represented in fig.3. The median value is 46 ng I/g creat.. 

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