Relationship of household cooking salt and eating out on iodine status of pregnant women in environmental iodine-deficient coastal areas of China

Abstract

As city residents eat out more frequently, it is unknown that if iodised salt is still required in home cooking. We analysed the relationship of household salt and eating out on urinary iodine concentration (UIC) in pregnant women. A household condiment weighing method was implemented to collect salt data for a week. A household salt sample was collected. A urine sample was taken at the end of the week. Totally, 4640 participants were investigated. The median UIC was 139·1 μg/l in pregnant women and 148·7, 140·0 and 122·9 μg/l in the first, second and third trimesters. Median UIC in the third trimester was lower than in the other trimesters (P < 0·001). The usage rates of iodised (an iodine content ≥ 5·0 mg/kg) and qualified-iodised (an iodine content ≥ 21·0 mg/kg) salt were 73·9 and 59·3 %. The median UIC in the qualified-iodised salt group was higher than in the non-iodised group (P = 0·037). The median UIC in the non-iodised group who did not eat out was lower than in qualified-salt groups who both did and did not eat out (P = 0·007, <0·001). The proportion of qualified-iodised salt used in home cooking is low, but foods eaten out have universal salt iodisation according to the national compulsory policy. Household iodised salt did not play a decisive role in the iodine status of pregnant women. Pregnant women in their third trimester who are not eating out and using non-iodised salt at home require extra iodine.

Association of maternal thyroid dysfunction and autoimmunity with adverse birth outcomes

“…We obtained the data from a pregnant study conducted in Shanghai, China from April to October 2017 [25]. The Ethical Committee of the Shanghai Center for Disease Control and Prevention approved the study (No.…”

Relationship of Trimester-Specific Maternal Thyroid Function With Gestational Weight Gain And Birth Weight In Pregnant Women With Normal Thyroid Autoimmunity

“…The present data was from a prospective birth cohort focusing on iodine nutritional status of pregnant women, thyroid function and the growth and development of their offspring in Shanghai, China, from April to October, 2017. A detailed description of the cohort is given in a previous paper [17]. This study was approved by the Ethical Committee of the Shanghai Center for Disease Control and Prevention (No.…”

Relationship of household cooking salt and eating out on iodine status of Chinese pregnant women in environmental iodine-deficient coastal areas

“…Although eating out has been associated with higher total energy and macronutrient intakes including fat, it is unclear if it may increase the consumption of iodine intake. This is because it depends on several factors including the frequency of eating out, the amount of iodised salt added during cooking and at the table . In Shanghai, the usage rates of iodised salt and qualifiediodised salt reported by the authors indicated a low coverage of iodised salt (< 90 %) (1)(2)(3) . In addition, only a small percentage of pregnant women (11•3 %) reported the use of iodine supplements (1) .…”

“…In Shanghai, the usage rates of iodised salt and qualified-iodised salt reported by the authors indicated a low coverage of iodised salt (< 90 %) (1–3) . In addition, only a small percentage of pregnant women (11·3 %) reported the use of iodine supplements (1) .…”

“…

This letter is regarding the recent publication of 'Relationship of household cooking salt and eating out on iodine status of pregnant women in environmental iodine-deficient coastal areas of China' by Wang et al (2020) (1) . The findings by the authors have provided an important research contribution to the body of observational evidence related to the relationship between the use of iodised salt at home and eating out on iodine status of pregnant women.

…”