Household Salt Storage and Seasoning Consumption Are Predictors of Insufficient Iodine Status Among Pregnant Women in Southeastern Brazil

Biological Trace Element Research https://doi.org/10.1007/s12011-023-03615-1 Household Salt Storage and Seasoning Consumption Are Predictors of Insufficient Iodine Status Among Pregnant Women in Southeastern Brazil Ana Carolina Momentti1 · Mariana de Souza Macedo2 · Ana Flávia de Sousa Silva1 · Vanessa Cristina de Oliveira Souza3 · Fernando Barbosa Júnior3 · Sylvia do Carmo Castro Franceschini2 Anderson Marliere Navarro4 · Received: 2 June 2022 / Accepted: 25 February 2023 © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023 Abstract Iodine deficiency in pregnancy may lead to adverse maternal and fetal outcomes, including impaired child development. Sociodemographic factors and different dietary habits may be related to iodine status in pregnant women. The aim of this study was to evaluate the iodine status and its predictors among pregnant women in a city of Southeastern Brazil. This crosssectional study was conducted with 266 pregnant women receiving prenatal care in 8 primary health care units. Sociodemographic, obstetric and health, habits of acquisition, storage and consumption of iodized salt, and dietary iodine intake data were collected through a questionnaire. The iodine content was evaluated in urinary iodine concentration (UIC), household salt and seasonings, and drinking water samples. Pregnant women were categorized into three groups according to the UIC, determined by iodine coupled plasma-mass spectrometry (ICP-MS): insufficient (< 150 μg/L), adequate (150–249 μg/L), and more than adequate iodine nutrition (≥ 250 μg/L). The median (p25–p75) UIC was 180.2 μg/L (112.8–262.7). It was found 38% and 27.8% of insufficient and more than adequate iodine nutrition, respectively. Number of gestations, KI content of supplement, alcohol consumption, salt storage, and frequency of using industrialized seasoning were associated to iodine status. Alcohol consumption (OR = 6.59; 95%CI 1.24–34.87), pack the salt in opened container (OR = 0.22; 95%CI 0.08–0.57), and use industrialized seasoning weekly (OR = 3.68; 95% CI 1.12–12.11) were predictors of iodine insufficiency. The pregnant women evaluated have adequate iodine nutrition. Household salt storage and seasoning consumption were risk factors for insufficient iodine status. Keywords Iodine status · Pregnancy · Urinary iodine concentration · Iodized salt · Brazil Introduction * Ana Carolina Momentti 1 Nutrition and Metabolism Program, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil 2 Department of Nutrition and Health, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil 3 Department of Clinical, Toxicological and Bromatological Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil 4 Department of Health Sciences, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil Iodine deficiency in pregnancy has been one of the major public health problems affecting developed and developing countries [1], and the most important preventable cause of brain damage [2]. Maternal daily iodine requirement increased by approximately 50% due to the elevated production of thyroid hormone, the enhanced iodine renal clearance, the requirement of fetal iodine, and the transference of iodine from the mother to the fetus [3, 4]. Therefore, the World Health Organization (WHO), the United Nations Children’s Fund (UNICEF) and the International Council for the Control of Iodine Deficiency Disorders (ICCIDD) recommend a daily iodine intake of 250 μg 13 Vol.:(0123456789) A. C. Momentti et al. to prevent iodine deficiency in pregnancy, in contrast to 100–150 μg for the general population [5]. The relevance of this issue concerns that iodine deficiency may lead to a wide spectrum of damage to maternal and child health, such as hypothyroidism, goiter, increased risk of miscarriage, perinatal and infant mortality, and neurocognitive and psychomotor deficits, collectively called iodine deficiency disorders (IDD) [1, 6]. The iodized salt is the main source of iodine in countries with fortification programs [7]. Universal salt iodization (USI) is a simple, effective and low cost method, and remains the primary strategy to achieve the goal of IDD elimination worldwide [8]. In Brazil, the USI is mandatory since 1956, and has been remarkably successful based on the relevant reduction in prevalence of goiter in school-age children, considered a proxy for the general population [9]. Currently, the country is considered a region of adequate iodine intake [10] not reflecting the iodine status in more vulnerable groups to the IDD, whereas studies conducted worldwide have been highlighting significant prevalences of iodine insufficiency in pregnant women [7, 10–12]. Sociodemographic factors and different dietary habits may be related to iodine status in pregnancy [13]. The urinary iodine concentration (UIC) is widely used in population surveys to assess the recent iodine status considering that more than 90% of the absorbed iodine is eliminated in the urine [6]. Regular monitoring of iodine status and the knowledge of its predictors in pregnant women are necessary to plan and execute specific actions against iodine deficiency. Furthermore, this evaluation should be carried out in different regions of Brazil, considering its large differences in socio-demographic, geographic, and climatic aspects. We aimed to evaluate the iodine status and the predictors of insufficient and more than adequate iodine nutrition among pregnant women from primary health care units in a city of Southeastern Brazil. Materials and Methods Study Design This is a cross-sectional study conducted with 266 pregnant women receiving prenatal care from May, 2019, to February, 2020, in 8 randomly selected primary health care units covering almost all regions of a city from Southeastern Brazil. The study is part of the Multicenter Study of Iodine Deficiency (EMDI-Brazil) aimed at assessing the status of iodine, sodium and potassium among pregnant women, mothers and infants groups in Brazilian macro-regions. 13 Participants Pregnant women aged ≥ 18 years old, at any gestational age, with no history of previous or current diagnosed thyroid disease and/or surgery were included in the study. The sample size was determined from a minimum proportion of 8%, with a relative error of 4% (range 4 to 12%) and a 95% confidence level, which led to a simple random sample of 177 pregnant women. As the sample was selected by primary health care unit, a design effect of 1.5 was included, which increased the sample size to 266 pregnant women. Informed consent was provided by all participants. Ethical approval was granted by the Ethics Committee of Hospital das Clinicas of Medical School of Ribeirão Preto – University of São Paulo (no. 3.252.310). Data Collection Sociodemographic; (...truncated)