title: Vitamin C, neutrophil function, and upper respiratory tract infection risk in distance runners: the missing link.
abstract: Moderate submaximal exercise results in neutrophilia and enhanced phagocytic and oxidative capacity of neutrophils. It has been hypothesized, however, that during intensive exercise and periods of intensive training this pro-oxidative effect becomes suppressive. Vitamin C is widely recognized for its antioxidant function in extracellular fluid, and it has been shown to neutralize O2-, HOCl, and .OH and to attenuate the suppression of phagocytic function. Clinical manifestation of reduced neutrophil function following participation in ultramarathon races has, however, not been observed. Although neutrophils constitute 50-60% of leukocytes and although they are the first line of defense to bacteriological invasion, postrace episodes of upper respiratory tract infection (URTI) are not correlated with a decrement in the function of this individual parameter of immune function. The efficacy of Vitamin C supplements in reducing the incidence of postrace URTI symptoms, therefore, cannot be fully explained at this stage.
authors.affiliation: Division of Physical Education, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: E M
authors.initials: EM
authors.lastname: Peters-Futre
mesh_terms: D000975:Antioxidants / Q000378:metabolism / Q000627:therapeutic use; D001205:Ascorbic Acid / Q000097:blood / Q000502:physiology* / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D004198:Disease Susceptibility; D006801:Humans; D007111:Immunity, Cellular; D007153:Immunologic Deficiency Syndromes / Q000097:blood / Q000209:etiology / Q000276:immunology / Q000517:prevention & control; D015994:Incidence; D007958:Leukocyte Count; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis; D016897:Respiratory Burst; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D012306:Risk; D012420:Running / Q000502:physiology*
chemical_list: D000975:Antioxidants; D001205:Ascorbic Acid