Analysis of iodine nutrition in residents of coastal and inland areas of Jiangsu Province / 中华地方病学杂志

ABSTRACT

Objective To master iodine intake ways of children in Yancheng (coastal) and Zhenjiang (inland) cities,analyze their urinary iodine difference and provide solid evidence for adjustment of salt iodine and adequate iodine intake level of local residents.Methods Totally 50％ counties were randomly selected in Yancheng and Zhenjiang cities and 5 towns were sampled in each county in 2014,local water iodine,domestic salt iodine,local eating habits and urine iodine of children 8-10 years old were investigated,and the influences of different iodine intake ways on urine iodine level were analyzed.Results The median of water iodine was 4.76 μg/Lin Zhenjiang (n =40) and 50.80 μg/L in Yancheng (n =50),the difference was statisticelly significant in two cities (Z =6.93,P ＜ 0.05).Totally 2 400 salt samples were tested,the mean of salt iodine was (24.20 ± 5.07) mg/kg in Yancheng (n =1 500) and (22.87 ± 2.77) mg/kg in Zhenjiang (n =900),the difference was statisticelly significant in two cityies (t =7.23,P ＜ 0.05).The salt intake level in Zhenjiang (10.69-± 9.00) g/d appeared to be higher than that in Yancheng (8.40 ± 3.57) g/d,but the difference was not statistically significant (t =1.62,P ＞ 0.05).Totally 1 200urine samples were tested,the urine iodine level of Zhenjiang got higher results (265.83 μg/L,n =450) than that of Yancheng (182.15 μg/L,n =750,Z =12.18,P ＜ 0.05).The ratio of water iodine intake/salt iodine intake was about 1 ∶ 4 in Yancheng and 1 ∶ 50 in Zhenjiang,while residents in Zhenjiang got 21％ of daily iodine through extra ways.Eating habits like eating out did not have significant impact on urine iodine.Conclusions Based on the water iodine level,Yancheng is considered to be a appropriate iodine level area while Zhenjiang is a lack region.However,Zhenjiang has a higher urine iodine level than Yancheng,which is more than adequate to the recommendation.Salt iodine is a main iodine source in both cities.In iodine appropriate and deficiency areas,eating habits and food choices may play a more important role than geochemical factors in iodine intakes among residents.