Iodine Status of Brazilian School-Age Children: A National Cross-Sectional Survey

Abstract

Salt iodization is the main public health policy to prevent and control iodine deficiency disorders. The National Salt Iodization Impact Assessment Survey (PNAISAL) was conducted to measure iodine concentration among Brazilian schoolchildren. A survey including 6–14-year-old schoolchildren from public and private schools from all 26 Brazilian states and the Federal District was carried out in the biennia 2008–2009 and 2013–2014. Municipalities, schools, and students were randomly selected. Students were interviewed at school using a standard questionnaire, which included the collection of demographic, educational, weight, height, and 10 mL non-fasting urine collection information. The analyses were weighted according to the population of students per federative unit. The median urinary iodine concentration (MUIC) for the entire sample by region, federative unit per school, and student characteristics, was described from the cutoff points defined by the World Health Organization (severe disability: <20 µg/L, moderate: 20–49 µg/L, mild: 50–99 µg/L, adequate: 100–199 µg/L, more than adequate: 200–299 µg/L, and excessive: >300 µg/L). In total, 18,864 students (95.9% of the total) from 818 schools in 477 municipalities from all federative units were included in this study. Almost 70% were brown skin color, nine-years-old or older, studied in urban schools, and were enrolled in elementary school. The prevalence of overweight/obesity, as measured by body mass index (BMI) for age, was about twice as high compared to nutritional deficits (17.3% versus 9.6%). The MUIC arrived at 276.7 µg/L (25th percentile = 175.5 µg/L and 75th percentile = 399.71 µg/L). In Brazil as a whole, the prevalence of mild, moderate, and severe deficit was 6.9%, 2.6%, and 0.6%, respectively. About one-fifth of the students (20.7%) had adequate iodine concentration, while 24.9% and 44.2% had more than adequate or excessive concentration, respectively. The prevalence of iodine deficits was significantly higher among younger female students from municipal public schools living in rural areas with the lowest BMI. The median urine iodine concentration showed that Brazilian students have an adequate nutritional intake, with a significant proportion of them evidencing overconsumption of this micronutrient.

GLOBAL ENDOCRINOLOGY: Global perspectives in endocrinology: coverage of iodized salt programs and iodine status in 2020

“…A good example is Brazil. In response to surveys in 1994–95 showing a 24% goiter rate in SAC, the iodine content in salt was increased to 40–100 ppm in 1998–1999 ( 30 ). As a result, in 2000, the mUIC in SAC was 360 μg/L, and the prevalence of goiter had fallen to 1.4%.…”

“…In the most recent national survey, which began in 2008–2009 and was completed in 2013–2014, the national mUIC was 277 µg/L, ranging from 248 µg/L in the South to 299 µg/L in the Northeast. In response, the fortification level of iodine in salt has been reduced to 15–45 mg ( 30 ). These Brazilian data highlight the value of regular monitoring of both salt iodization programs and of population iodine status.…”

Características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia

“…nas tiroideas necesarias para el crecimiento y desarrollo celular, especialmente las células nerviosas (1) .…”

“…En Colombia se han realizado estudios puntuales en lugares como Popayán (n=139) en donde destaca una mediana en la yoduria de 510,3 μg/L (8) y en Quindío (n=444) en donde se mostró severas deficiencias (zonas rurales) y excesiva ingesta de yodo (población urbana) (9) . En el 2002 se realizó un estudio centinela en el que se mostró que el 85% de la población nacional tenía una ingesta excesiva de yodo (1) y recientemente en la Encuesta de la Situación Nutricional de Colombia 2015, se actualizó la información de la situación de nutrición del yodo en la población colombiana y se reiteró la situación de exceso en población escolar y adolescente colombiana.…”

Concentration of iodine in iodized salt and estimation in school meals in a region of northeast Brazil

“…Since the implementation of this policy, some studies have been conducted to assess the impact of this intervention on the reduction of endemic goiter, and the results indicated a reduction in the prevalence of goiter, showing the efficiency of iodized salt, especially after the increased distribution of iodized salt throughout the territory (Alves et al, 2018;Cesar et al, 2020). In 1999, the Brazilian Government changed the iodine content to 40-100 mg/kg of salt, as the previous amount was no longer considered enough to achieve the minimum necessary concentration (Alves, 2020).…”