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Iron excess in recreational marathon runners

Abstract

Background/Objectives:

Iron deficiency and anemia may impair athletic performance, and iron supplements are commonly consumed by athletes. However, iron overload should be avoided because of the possible long-term adverse health effects.

Methods:

We investigated the iron status of 170 male and female recreational runners participating in the Zürich marathon. Iron deficiency was defined either as a plasma ferritin (PF) concentration <15 μg/l (iron depletion) or as the ratio of the concentrations of transferrin receptor (sTfR) to PF (sTfR:log(PF) index) of 4.5 (functional iron deficiency).

Results:

After excluding subjects with elevated C-reactive protein concentrations, iron overload was defined as PF >200 μg/l. Iron depletion was found in only 2 out of 127 men (1.6% of the male study population) and in 12 out of 43 (28.0%) women. Functional iron deficiency was found in 5 (3.9%) and 11 (25.5%) male and female athletes, respectively. Body iron stores, calculated from the sTfR/PF ratio, were significantly higher (P<0.001) among male compared with female marathon runners. Median PF among males was 104 μg/l, and the upper limit of the PF distribution in males was 628 μg/l. Iron overload was found in 19 out of 127 (15.0%) men but only 2 out of 43 in women (4.7%). Gender (male sex), but not age, was a predictor of higher PF (P<0.001).

Conclusions:

Iron depletion was present in 28% of female runners but in <2% of males, whereas one in six male runners had signs of iron overload. Although iron supplements are widely used by athletes in an effort to increase performance, our findings indicate excess body iron may be common in male recreational runners and suggest supplements should only be used if tests of iron status indicate deficiency.

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References

  • Baech SB, Hansen M, Bukhave K, Jensen M, Sorensen SS, Kristensen L et al. (2003). Nonheme-iron absorption from a phytate-rich meal is increased by the addition of small amounts of pork meat. Am J Clin Nutr 77, 173–179.

    CAS  Article  PubMed  Google Scholar 

  • Baynes RD (1996). Assessment of iron status. Clin Biochem 29, 209–215.

    CAS  Article  PubMed  Google Scholar 

  • Beard J, Tobin B (2000). Iron status and exercise. Am J Clin Nutr 72, 594S–597S.

    CAS  Article  PubMed  Google Scholar 

  • Brownlie T, Utermohlen V, Hinton PS, Giordano C, Haas JD (2002). Marginal iron deficiency without anemia impairs aerobic adaptation among previously untrained women. Am J Clin Nutr 75, 734–742.

    CAS  Article  PubMed  Google Scholar 

  • Brownlie T, Utermohlen V, Hinton PS, Haas JD (2004). Tissue iron deficiency without anemia impairs adaptation in endurance capacity after aerobic training in previously untrained women. Am J Clin Nutr 79, 437–443.

    CAS  Article  PubMed  Google Scholar 

  • Colombani PC, Mannhart C (2003). Energie- Und Nährstoffaufnahme Im Schweizer Spitzensport—Eine Erste Bestandsaufnahme Zu Beginn Des Zweiten Jahrtausends. Schweiz Z Sportmed Sporttraum 51, 7–15.

    Google Scholar 

  • Cook JD, Flowers CH, Skikne BS (2003). The quantitative assessment of body iron. Blood 101, 3359–3364.

    CAS  Article  PubMed  Google Scholar 

  • Deugnier Y, Loreal O, Carre F, Duvallet A, Zoulim F, Vinel JP et al. (2002). Increased body iron stores in elite road cyclists. Med Sci Sports Exerc 34, 876–880.

    Article  PubMed  Google Scholar 

  • Dubnov G, Constantini NW (2004). Prevalence of iron depletion and anemia in top-level basketball players. Int J Sport Nutr Exerc Metab 14, 30–37.

    CAS  Article  PubMed  Google Scholar 

  • Ehn L, Carlmark B, Hoglund S (1980). Iron status in athletes involved in intense physical activity. Med Sci Sports Exerc 12, 61–64.

    CAS  Article  PubMed  Google Scholar 

  • Eichner ER (2000). Minerals: iron. In: Maughan RJ (ed). Nutrition in Sport. Blackwell Science: Oxford.

    Google Scholar 

  • Ferguson BJ, Skikne BS, Simpson KM, Baynes RD, Cook JD (1992). Serum transferrin receptor distinguishes the anemia of chronic disease from iron deficiency anemia. J Lab Clin Med 119, 385–390.

    CAS  PubMed  Google Scholar 

  • Fielding J (1980). Serum iron and iron binding capacity. In: Cook JD (ed). Iron, Methods in Hematology. Churchill Livingstone: New York, NY. pp 15–43.

    Google Scholar 

  • Hinton PS, Giordano C, Brownlie T, Haas JD (2000). Iron supplementation improves endurance after training in iron-depleted, nonanemic women. J Appl Physiol 88, 1103–1111.

    CAS  Article  PubMed  Google Scholar 

  • Huang SH, Johnson K, Pipe AL (2006). The use of dietary supplements and medications by Canadian athletes at the Atlanta and Sydney Olympic Games. Clin J Sport Med 16, 27–33.

    Article  PubMed  Google Scholar 

  • Klipstein-Grobusch K, Koster JF, Grobbee DE, Lindemans J, Boeing H, Hofman A et al. (1999). Serum ferritin and risk of myocardial infarction in the elderly: the Rotterdam Study. Am J Clin Nutr 69, 1231–1236.

    CAS  Article  PubMed  Google Scholar 

  • Lippi G, Schena F, Franchini M, Salvagno GL, Guidi GC (2005). Serum ferritin as a marker of potential biochemical iron overload in athletes. Clin J Sport Med 15, 356–358.

    Article  PubMed  Google Scholar 

  • Lukaski HC (2004). Vitamin and mineral status: effects on physical performance. Nutrition 20, 632–644.

    CAS  Article  PubMed  Google Scholar 

  • Lyle RM, Weaver CM, Sedlock DA, Rajaram S, Martin B, Melby CL (1992). Iron status in exercising women: the effect of oral iron therapy vs increased consumption of muscle foods. Am J Clin Nutr 56, 1049–1055.

    CAS  Article  PubMed  Google Scholar 

  • Malczewska J, Blach W, Stupnicki R (2000a). The effects of physical exercise on the concentrations of ferritin and transferrin receptor in plasma of female judoists. Int J Sports Med 21, 175–179.

    CAS  Article  PubMed  Google Scholar 

  • Malczewska J, Raczynski G, Stupnicki R (2000b). Iron status in female endurance athletes and in non-athletes. Int J Sport Nutr Exerc Metab 10, 260–276.

    CAS  Article  PubMed  Google Scholar 

  • McCord JM (1998). Iron, free radicals, and oxidative injury. Semin Hematol 35, 5–12.

    CAS  PubMed  Google Scholar 

  • Merkel D, Huerta M, Grotto I, Blum D, Tal O, Rachmilewitz E et al. (2005). Prevalence of iron deficiency and anemia among strenuously trained adolescents. J Adolesc Health 37, 220–223.

    Article  PubMed  Google Scholar 

  • Mettler S, Rusch C, Frey WO, Bestmann L, Wenk C, Colombani PC (2008). Hyponatremia among runners in the Zurich marathon. Clin J Sport Med 18, 344–349.

    Article  PubMed  Google Scholar 

  • Newhouse IJ, Clement DB (1988). Iron status in athletes. An update. Sports Med 5, 337–352.

    CAS  Article  PubMed  Google Scholar 

  • Newhouse IJ, Clement DB, Taunton JE, McKenzie DC (1989). The effects of prelatent/latent iron deficiency on physical work capacity. Med Sci Sports Exerc 21, 263–268.

    CAS  Article  PubMed  Google Scholar 

  • Nielsen P, Nachtigall D (1998). Iron supplementation in athletes. Current recommendations. Sports Med 26, 207–216.

    CAS  Article  PubMed  Google Scholar 

  • Petersen HL, Peterson CT, Reddy MB, Hanson KB, Swain JH, Sharp RL et al. (2006). Body composition, dietary intake, and iron status of female collegiate swimmers and divers. Int J Sport Nutr Exerc Metab 16, 281–295.

    CAS  Article  PubMed  Google Scholar 

  • Pietrangelo A (2004). Hereditary hemochromatosis—a new look at an old disease. N Engl J Med 350, 2383–2397.

    CAS  Article  PubMed  Google Scholar 

  • Rodenberg RE, Gustafson S (2007). Iron as an ergogenic aid: ironclad evidence? Curr Sports Med Rep 6, 258–264.

    PubMed  Google Scholar 

  • Salonen JT, Nyyssonen K, Korpela H, Tuomilehto J, Seppanen R, Salonen R (1992). High stored iron levels are associated with excess risk of myocardial infarction in eastern Finnish men. Circulation 86, 803–811.

    CAS  Article  PubMed  Google Scholar 

  • Schumacher YO, Schmid A, Grathwohl D, Bultermann D, Berg A (2002). Hematological indices and iron status in athletes of various sports and performances. Med Sci Sports Exerc 34, 869–875.

    Article  PubMed  Google Scholar 

  • Schumann K, Ettle T, Szegner B, Elsenhans B, Solomons NW (2007). On risks and benefits of iron supplementation recommendations for iron intake revisited. J Trace Elem Med Biol 21, 147–168.

    Article  PubMed  Google Scholar 

  • Sinclair LM, Hinton PS (2005). Prevalence of iron deficiency with and without anemia in recreationally active men and women. J Am Diet Assoc 105, 975–978.

    CAS  Article  PubMed  Google Scholar 

  • Suedekum NA, Dimeff RJ (2005). Iron and the athlete. Curr Sports Med Rep 4, 199–202.

    Article  PubMed  Google Scholar 

  • Thankachan P, Walczyk T, Muthayya S, Kurpad AV, Hurrell RF (2008). Iron absorption in young Indian women: the interaction of iron status with the influence of tea and ascorbic acid. Am J Clin Nutr 87, 881–886.

    CAS  Article  PubMed  Google Scholar 

  • Tuomainen TP, Loft S, Nyyssonen K, Punnonen K, Salonen JT, Poulsen HE (2007). Body iron is a contributor to oxidative damage of DNA. Free Radic Res 41, 324–328.

    CAS  Article  PubMed  Google Scholar 

  • WHO (2001). Iron deficiency anemia. In: Methods of Assessing Iron Status. World Health Organisation. pp 33–46.

  • Zimmermann MB, Hurrell RF (2007). Nutritional iron deficiency. Lancet 370, 511–520.

    CAS  Article  PubMed  Google Scholar 

  • Zoller H, Vogel W (2004). Iron supplementation in athletes—first do no harm. Nutrition 20, 615–619.

    CAS  Article  PubMed  Google Scholar 

  • Zotter H, Robinson N, Zorzoli M, Schattenberg L, Saugy M, Mangin P (2004). Abnormally high serum ferritin levels among professional road cyclists. Br J Sports Med 38, 704–708.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We thank the subjects who participated in the study. We also thank Myrtha Arnold, Christophe Zeder and Jeannine Baumgartner (Zürich, Switzerland) for technical and analytical support. This study was funded by the Swiss Foundation for Nutrition Research, Zürich, Switzerland.

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Correspondence to M B Zimmermann.

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Mettler, S., Zimmermann, M. Iron excess in recreational marathon runners. Eur J Clin Nutr 64, 490–494 (2010). https://doi.org/10.1038/ejcn.2010.16

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  • DOI: https://doi.org/10.1038/ejcn.2010.16

Keywords

  • iron
  • exercise
  • performance
  • ferritin

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