Selenium intake, food sources, and associated factors in Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): a cross-sectional study.

Background: Selenium is essential to human health. There are few reports on the analysis of selenium intake in the Brazilian population; however, data have shown that Brazilian are in the deficient range of consumption.

Objectives: This study aimed to identify the major foods that contribute to dietary selenium and determine the socioeconomic and lifestyle factors associated with selenium intake.

Design and setting: This cross-sectional study used baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Methods: Selenium consumption was evaluated using a food frequency questionnaire (FFQ) developed and validated for the ELSA-Brasil. To determine the contribution of selenium consumption, each food item was divided by the total selenium intake of the population. Associations between selenium intake (mg/day, dependent variable) and sociodemographic and lifestyle factors (predictors) were tested using multiple linear regression analyses.

Results: The sample comprised 14,780 participants, most of whom were adults (78.5%). Individuals with income ≥ 3 minimum wages were mostly concentrated in the 5th quintile of selenium consumption; positive and significant correlations were found between selenium intake and female sex, age ≥ 60 years, income ≥ 3 minimum wages, higher or postgraduate education, alcohol consumption, and moderate physical activity level. Nuts and fish contributed the most to dietary selenium.

Conclusion: Nuts, meat, and fish contributed the most to the dietary intake of selenium, and selenium intake was associated with sociodemographic and lifestyle factors among the evaluated individuals.