A Preliminary Predictive Model for Selenium Nutritional Status in Residents Based on Three Selenium Biomarkers.

Background: Selenium (Se) is an essential nutrient and an important component of many selenoproteins that possess fundamental importance to human health. Selenium deficiency and excess will cause corresponding diseases in the human body. The nutritional health of Se in the human body mainly depends on the daily dietary Se intake of the human body, which in turn depends to a certain extent on the content of Se transmitted along the food chain. This study aims to research the transport of Se through the soil-crop-human chain in regions with different Se levels, and to establish the model between the residents' dietary Se intake and the three Se bio-markers (hair, nails, and plasma), to predict the nutritional health status of Se in residents through Se biomarkers.Method: Carry out field and cross-sectional surveys of populations in Loujiaba Village and Longshui Village. Samples were collected from soil, crops, drinking water, residents' hair, nails, plasma, and diet. The concentration of available Se fractions was extracted from soil samples using 0.1 mol/L K2HPO4. The concentration of total Se for all samples was determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and the relative standard deviation was less than 5%. In this study, hair, nails, and blood samples were collected from volunteers according to the Declaration of Helsinki and the Ethics Committee of Soochow University. The dietary nutritional structure and dietary Se intake of the population were randomly selected by 12 volunteers using the duplicate portion method. Data were described using mean +/- standard deviation. We performed saliency analysis and correlation analysis (with Pearson correlation coefficient), and fitted a regression to evaluate the associations between these variables.Results: The soil total Se (5201 +/- 609.2 mu g/kg) and available Se (307.7 +/- 83.5 mu g/kg) in Luojiaba Village (LJB) were significantly higher than the soil total Se (229.2 +/- 32.5 mu g/kg) and available Se (21.9 +/- 4.0 mu g/kg) in Longshui Village (LS). The residents' dietary Se intake of LJB (150.3 +/- 2.2 mu g/d) was within the World Health Organization (WHO) recommended intake range, while LS (16.0 +/- 0.4 mu g/d) was close to the range of Keshan disease occurrence, and there was a risk of insufficient Se intake. The correlation analysis found significant positive correlations between residents' dietary Se intake and the three Se biomarkers. According to the preliminary model established in this study, if the daily dietary Se intake of residents reaches the WHO recommended value of 55-400 mu g, the hair, nails, and plasma of Se concentration will be 522.1-2850.5 mu g/kg, 1069.0-6147.4 mu g/kg, and 128.3-661.36 mu g/L, respectively.