title: Influence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathon.
abstract: This randomized study measured the influence of vitamin C ( N=15) compared to placebo ( N=13) supplementation on oxidative and salivary immunoglobulin A (sIgA) changes in runners competing in an ultramarathon race. Seven days prior to the race, subjects ingested in randomized, double-blind fashion three 500-mg tablets of vitamin C or placebo each day. On race day, blood and saliva samples were collected 1 h pre-race, after 32 km of running, and then again immediately post-race. During the race, runners received 1 l/h carbohydrate beverages (60 g/l) with vitamin C (150 mg/l) or without in a double-blinded fashion. The runners also ingested two to three carbohydrate gel packs per hour (25 g each). Subjects in both groups ran a mean of 69 km (range 48-80 km) in 9.8 h (range 5-12 h) and maintained an intensity of approximately 75% maximal heart rate (HR(max)) throughout the ultramarathon race. Plasma ascorbic acid was higher in the vitamin C compared to placebo group pre-race, and increased significantly in the vitamin C group during the race [post-race, 3.21 (0.29) and 1.28 (0.12) microg/100 microl, respectively, P<0.001]. No significant group or interaction effects were measured for lipid hydroperoxide and F(2)-isoprostane, but both oxidative measures rose significantly during the ultramarathon race. Saliva volume, sIgA concentration, sIgA secretion and sIgA:saliva protein ratio all decreased significantly (P<0.001) during the race, but the pattern of change in all saliva measures did not differ significantly between groups. No significant correlations were found between post-race plasma vitamin C, oxidative, and saliva measures, except for a positive correlation between post-race serum cortisol and serum vitamin C (r=0.50, P=0.006). These data indicate that vitamin C supplementation in carbohydrate-fed runners does not serve as a countermeasure to oxidative and sIgA changes during or following a competitive ultramarathon race.
authors.affiliation: Department of Health, Leisure and Exercise Science, Appalachian State University, PO Box 32071, Boone, NC 28608, USA.
authors.forename: Franziska M
authors.initials: FM
authors.lastname: Palmer
authors.forename: David C
authors.initials: DC
authors.lastname: Nieman
authors.forename: Dru A
authors.initials: DA
authors.lastname: Henson
authors.forename: Stephen R
authors.initials: SR
authors.lastname: McAnulty
authors.forename: Lis
authors.initials: L
authors.lastname: McAnulty
authors.forename: Nathaniel S
authors.initials: NS
authors.lastname: Swick
authors.forename: Alan C
authors.initials: AC
authors.lastname: Utter
authors.forename: Debra M
authors.initials: DM
authors.lastname: Vinci
authors.forename: Jason D
authors.initials: JD
authors.lastname: Morrow
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000097:blood* / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D007074:Immunoglobulin G / Q000097:blood* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012420:Running / Q000502:physiology*; D012463:Saliva / Q000378:metabolism*
chemical_list: D007074:Immunoglobulin G; D001205:Ascorbic Acid; D006854:Hydrocortisone