Nutritional selenium status in a cohort of university students: impact on intellectual and cognitive performance.

Evidence on selenium status and cognitive performance in university populations remains limited. We examined dietary intake and serum selenium concentration, and their associations with cognitive performance in Spanish university students. A cross-sectional study was conducted in 132 students aged 18-29 years. Participants completed a dietary record to estimate selenium intake. Cognitive performance was assessed using the WAIS-IV, including the Total Intelligence Quotient (mean TIQ = 90) and its cognitive indices. Serum selenium status was classified according to a reference adequacy threshold of 80 μg/L. Associations between selenium status and cognitive outcomes were evaluated using Spearman correlations and linear regression models. The 53.5% of female and 16.4% of male fell below the reference serum value. Students with TIQ < 90 had lower serum selenium than those with TIQ ≥ 90 (84.9 ± 16.9 vs. 93.3 ± 21.4 μg/L). Serum selenium was positively correlated with TIQ, Verbal Comprehension index "VCI" and Working Memory "WMI." Dietary selenium intake correlated with VCI. In adjusted models, male sex and higher energy intake were positively associated with TIQ, whereas selenium intake showed an inverse association with TIQ (β = -0.067 points/μg/day) and Perceptual Reasoning Index "PRI" (β = -0.129 points/μg/day), and was not independently associated with VCI, WMI, or Processing Speed Index "PSI." Selenium intake and serum selenium were associated with cognitive outcomes in unadjusted analyses, while adjusted models suggested a more complex relationship. A substantial proportion of female exhibited low serum selenium levels, underscoring the importance of monitoring selenium status in young adults and warranting confirmation in longitudinal studies.