title: Differential responses to selenomethionine supplementation by sex and genotype in healthy adults.
abstract: A year-long intervention trial was conducted to characterise the responses of multiple biomarkers of Se status in healthy American adults to supplemental selenomethionine (SeMet) and to identify factors affecting those responses. A total of 261 men and women were randomised to four doses of Se (0, 50, 100 or 200 μg/d as L-SeMet) for 12 months. Responses of several biomarkers of Se status (plasma Se, serum selenoprotein P (SEPP1), plasma glutathione peroxidase activity (GPX3), buccal cell Se, urinary Se) were determined relative to genotype of four selenoproteins (GPX1, GPX3, SEPP1, selenoprotein 15), dietary Se intake and parameters of single-carbon metabolism. Results showed that supplemental SeMet did not affect GPX3 activity or SEPP1 concentration, but produced significant, dose-dependent increases in the Se contents of plasma, urine and buccal cells, each of which plateaued by 9-12 months and was linearly related to effective Se dose (μg/d per kg0·75). The increase in urinary Se excretion was greater for women than men, and for individuals of the GPX1 679 T/T genotype than for those of the GPX1 679 C/C genotype. It is concluded that the most responsive Se-biomarkers in this non-deficient cohort were those related to body Se pools: plasma, buccal cell and urinary Se concentrations. Changes in plasma Se resulted from increases in its non-specific component and were affected by both sex and GPX1 genotype. In a cohort of relatively high Se status, the Se intake (as SeMet) required to support plasma Se concentration at a target level (Se(pl-target)) is: Se(in) = [(Se(pl - target) - Se(pl))/(18.2ng d kg⁰.⁷⁵/ml per mu g)] .
authors.affiliation: Grand Forks Human Nutrition Research Center, USDA-ARS, 2420 2nd Avenue North, Stop 9034, Grand Forks, ND 58202-9034, USA. gerald.combs@ars.usda.gov
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Combs
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Jackson
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Watts
authors.forename: LuAnn K
authors.initials: LK
authors.lastname: Johnson
authors.forename: Huawei
authors.initials: H
authors.lastname: Zeng
authors.forename: Joseph
authors.initials: J
authors.lastname: Idso
authors.forename: Lutz
authors.initials: L
authors.lastname: Schomburg
authors.forename: Antonia
authors.initials: A
authors.lastname: Hoeg
authors.forename: Carolin S
authors.initials: CS
authors.lastname: Hoefig
authors.forename: Emily C
authors.initials: EC
authors.lastname: Chiang
authors.forename: David J
authors.initials: DJ
authors.lastname: Waters
authors.forename: Cindy D
authors.initials: CD
authors.lastname: Davis
authors.forename: John A
authors.initials: JA
authors.lastname: Milner
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005838:Genotype; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000166:cytology / Q000378:metabolism; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism; D012643:Selenium / Q000097:blood / Q000378:metabolism* / Q000652:urine; D012645:Selenomethionine / Q000493:pharmacokinetics*; D051149:Selenoprotein P / Q000378:metabolism; D051140:Selenoproteins / Q000235:genetics* / Q000378:metabolism; D012737:Sex Factors; D000094765:Glutathione Peroxidase GPX1
chemical_list: D015415:Biomarkers; D051149:Selenoprotein P; D051140:Selenoproteins; D002244:Carbon; D012645:Selenomethionine; C486484:GPX3 protein, human; D005979:Glutathione Peroxidase; D012643:Selenium; D000094765:Glutathione Peroxidase GPX1; C000722067:GPX1 protein, human