title: Evidence of zinc deficiency in competitive swimmers.
abstract: OBJECTIVE
  The aim of this study was to assess the nutritional zinc (Zn) status of elite swimmers during different training periods.
  
  
  METHODS
  A longitudinal paired study was performed at the University of Sao Paulo in eight male swimmers 18 to 25 y old who had been swimming competitively at the state and national levels for at least 5 y. The swimmers were evaluated over a total period of 14 wk: before the basic and specific preparatory period (BSPP-baseline), at the end of the basic and specific preparatory period (post-BSPP), and at the end of the polishing period (PP). Levels of Zn were determined in the plasma, erythrocyte, urine, and saliva by atomic absorption spectrophotometry. Anthropometric measurements and a 3-d food record were also evaluated.
  
  
  RESULTS
  The median plasma Zn concentration was below the reference value in all training periods (BSPP-baseline 59 μg/dL, post-BSPP 55.9 μg/dL, after PP 58.8 μg/dL, P > 0.05), as were threshold values for erythrocytes (BSPP-baseline 36.5 μg of Zn/g of hemoglobin, post-BSPP 42 μg of Zn/g of hemoglobin, after PP 40.7 μg of Zn/g of hemoglobin, P > 0.05), urinary Zn (BSPP-baseline 280 μg/24 h, post-BSPP 337 μg/24 h, after PP 284 μg/24 h, P > 0.05), and salivary Zn (BSPP-baseline 66.1 μg/L, post-BSPP 54.1 μg/L, after PP 79.7 μg/L, P > 0.05). Salivary Zn did not correlate with plasma and erythrocyte Zn levels.
  
  
  CONCLUSIONS
  The results suggest that the elite swimmers studied presented a possible Zn deficiency and that salivary Zn was not adequate to evaluate the Zn nutritional status.
authors.affiliation: Department of Food and Nutrition, State University of São Paulo, Araraquara, São Paulo, Brazil. flaviagiolo@gmail.com
authors.forename: Flávia
authors.initials: F
authors.lastname: Giolo De Carvalho
authors.forename: Flávia Troncon
authors.initials: FT
authors.lastname: Rosa
authors.forename: Vivian
authors.initials: V
authors.lastname: Marques Miguel Suen
authors.forename: Ellen Cristini
authors.initials: EC
authors.lastname: Freitas
authors.forename: Gilberto José
authors.initials: GJ
authors.lastname: Padovan
authors.forename: Julio Sérgio
authors.initials: JS
authors.lastname: Marchini
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001938:Brazil; D004032:Diet / Q000009:adverse effects* / Q000208:ethnology; D015930:Diet Records; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009752:Nutritional Status / Q000208:ethnology; D015203:Reproducibility of Results; D012463:Saliva / Q000378:metabolism; D013054:Spectrophotometry, Atomic; D013550:Swimming; D055815:Young Adult; D015032:Zinc / Q000008:administration & dosage / Q000172:deficiency* / Q000378:metabolism
chemical_list: D015032:Zinc