title: Increase in selenium requirements with physical activity loads in well-trained athletes is not linear.
abstract: Selenium requirements in athletes are supposed to be increased with energy expenditure (EE) to preserve selenium status and an optimal antioxidant balance. The question of whether selenium intakes are related to EE and whether plasma selenium status induces up-regulation in erythrocyte endogenous antioxidant defense and decreases plasma oxidative damage markers in athletes was addressed. 118 well-trained athletes completed 7 d food and activities records in a cross-sectional study. Blood was sampled on day 8. Among the athletes, 23% of the males and 66% of the females had selenium intakes below two-third of the French RDA. Plasma selenium concentrations in most of less trained athletes were lower than the postulated concentration to be required to maximize erythrocyte GSH-Px activity. Athletes with the highest daily EE had the highest selenium intakes, percentage of vegetal protein intakes and plasma selenium concentrations. Only 2.6% of the athletes exhibited low plasma selenium concentrations (< 0.75 micromol/l). The relation between plasma selenium and EE was polynomial (r = 0.50; P < 0.005). Erythrocyte GSH-Px activity in athletes was not linked to selenium status. Selenium requirements are increased in athletes without being linearly related to EE.
authors.affiliation: Laboratoire Physiologie des Adaptations, Performance Motrice et Santé, Faculté des Sciences du Sport, Université de Nice-Sophia-Antipolis, Nice, France. Irini.Margaritis@unice.fr
authors.forename: Irène
authors.initials: I
authors.lastname: Margaritis
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Rousseau
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hininger
authors.forename: Stéphane
authors.initials: S
authors.lastname: Palazzetti
authors.forename: Josiane
authors.initials: J
authors.lastname: Arnaud
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Roussel
mesh_terms: D000328:Adult; D004032:Diet; D004734:Energy Metabolism; D004912:Erythrocytes / Q000201:enzymology; D015444:Exercise; D005260:Female; D005602:France; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D018673:Nutrition Policy; D009751:Nutritional Requirements; D012643:Selenium / Q000008:administration & dosage* / Q000097:blood; D013177:Sports
chemical_list: D005979:Glutathione Peroxidase; D012643:Selenium