Usual intake and dietary sources of Selenium in adolescents: A cross-sectional school-based study

Selenium is a mineral that constitutes selenoproteins and, therefore, has been studied, especially in cardiovascular diseases. Some risk factors for the development of these diseases, such as obesity, hypertension and dyslipidemia, have been observed early in life, including in childhood and adolescence, and food and nutrient intake is an important associated factor for their development. The aim of this study was to assess usual intake of selenium (Se) and dietary inadequacies regarding the consumption of this mineral, and to identify the main dietary sources of Se among 12-17 year-old Brazilian adolescents.

Data from the Study of Cardiovascular Risk in Adolescents, performed countrywide in the years 2013 and 2014, were used to estimate inadequate Se dietary intake. The National Cancer Institute's method was used, considering two days of 24 h dietary recall (24hR). The contribution of each food group to the total intake of Se was determined using a single 24hR, and was defined as a ratio between the total intake of Se and the percentage of Se in each food group, until reaching 95%. Food mentioned by adolescents were categorized into 39 food groups, according to macronutrient similarities.

Data from 76,957 adolescents aged from 12-17 years (49.7% girls) from public and private schools were assessed. Selenium intake was according to recommendation levels. Mean Se intake ranged from 84.3 to 105.9 μg among sex and age groups. Considering the whole sample, meat, pasta, poultry, and fish were the food groups that contributed with the greatest amount of Se (representing 57.9% of total Se). Brazil nuts are consumed in bigger quantity only by 14-17 year-old girls, contributing to 1.6% of the Se in their diets.

Brazilian adolescents have an adequate Se intake because of the high consumption of meat, pasta, and poultry. Although Brazil nuts are the most important dietary source of Se, adolescents consume them in very small amounts, leading to a small contribution in the total intake.