Iodine Deficiency in Zhejiang Pregnant Women in the Context of Universal Salt Iodization Programme

Abstract

Zhejiang introduced universal salt iodization (USI) programme in 1995 and has achieved the goal of elimination of iodine deficiency disorders (IDD) since 2011. However, no systematical data of iodine nutritional status in population in pregnancy is available. In this cross-sectional study, pregnant women were interviewed to complete questionnaires in addition to handing in samples of urine and household table salt between March 2016 to February 2017. Date of birth, age of pregnancy, ethnicity and dietary iodine habits were recorded. The overall median urinary iodine concentration in 8561 pregnant women was 130.47 µg/L, which was lower than the cut-off value of iodine sufficiency of 150 µg/L recommended by the WHO. Participants using non-iodized salt, taking non-iodine-containing supplements, in coastal and in Han group were independently associated with iodine deficiency. The current USI programme did not supply Zhejiang pregnant women with sufficient iodine intake. They are generally iodine deficient, which have great public health importance since even mild IDD in pregnancy have adverse effects on fetal neurodevelopment. We strongly recommend urgent measures to improve iodine intake in pregnancy.

Geographical influences on the iodine status in pregnant women, neonates, and school-age children in China

“…This study also shows that the pregnant population remain iodine-deficient when consuming 25 ppm iodized salt. This finding is in line with our previous IDD surveillance results from pregnant women in Zhejiang Province [14,15]. Nevertheless, the finding in this study is not consistent with the results from the three other provinces (Shandong, Shanxi and Jiangsu), where pregnant women were iodine-sufficient when they consumed 25 ppm iodized salt [11]..…”

“…For pregnant women and school-age children, stratified random sampling was performed. The sampling followed the WHO's and Chinese IDD surveillance guidelines [6,13], and the details have been provided in our previous studies [14,15]. Briefly, a total of eighteen counties from these two regions were selected.…”

Current iodine nutrition status in Poland (2017): is the Polish model of obligatory iodine prophylaxis able to eliminate iodine deficiency in the population?

“…Therefore, the efficacy of iodine prophylaxis programmes should be monitored on a regular basis, and the iodine content in salt adjusted accordingly to the obtained results (83,84) . It needs to be remembered that a profound decrease in iodine content in salt may trigger a return of iodine deficiency (as was observed in pregnant women in the Zhejiang province of China after a reduction of iodine content from 35 to 25 ppm) (85) .…”

Low intake of iodized salt and iodine containing supplements among pregnant women with apparently insufficient iodine status - time to change policy?

“…Importantly, it is currently unclear whether fortification alone can provide adequate iodine intake during pregnancy and lactation [39,42,43], and the range of appropriate iodine levels is narrow. Moreover, if a country moves ahead with a Universal Salt Iodization Program, then its ICS recommendations for PW must be carefully calibrated so that women of child bearing age and PW get the appropriate amount of iodine neither too little nor too much [39,[43][44][45][46][47][48]. Intake of both IS and ICS, together with other iodine rich food sources, may potentially lead to excessive iodine intake [16,30,39,49] 1 .…”

“…Adopt WHO guidelines for iodization of salt and the development of a national universal salt iodization program, in coordination with the ICS recommendations for PW [38,39,[44][45][46][47]50]; Encourage cooperative industry engagement using regulation and financial incentives [43]; Initiate a professional advisory board composed of clinicians, public policy makers and industry representatives; Promote ICS adherence and knowledge of dietary iodine sources by caregivers and possibly by health maintenance organizations; Promote awareness (among both professionals and pregnant women themselves) of the importance of adequate iodine intake during pregnancy; accelerating public health information campaign and professional education initiatives; Institute appropriate regulations and a monitoring program to ensure adequate and safe fortification and supplementation [37].…”