Changes in iron status during competitive season in female collegiate swimmers.
We examined changes in iron status in 25 female varsity collegiate swimmers over the course of a competitive season via weekly capillary blood sampling. We also studied the effectiveness of moderate iron supplementation (39 mg/day) in preventing expected changes in iron status via a double-blinded crossover design. On entry into the study, 17 of the swimmers had depleted iron stores (plasma ferritin < 12 micrograms/L) and 5 were anemic (Hb < 120 g/L). After 5 wk of placebo treatment, hemoglobin decreased (> or = 6 g/L) in 44% and increased in 12% of the subjects. After 5 wk of iron supplementation, hemoglobin decreased in 16% and increased in 24% of the subjects. Likewise, after placebo treatment, plasma ferritin decreased (> or = 5 micrograms/L) in 24% and increased in 4% of the subjects, whereas iron supplementation resulted in decreases in 4% and increases in 68% of the subjects. In the absence of iron supplementation, hemoglobin levels decreased despite mean dietary iron intakes of 16.3 mg/day. These results show that moderate iron supplementation is effective in preventing decline in the iron status of female collegiate swimmers during a competitive season, but a higher dose of iron may be necessary to reverse their iron-deficient state.
Brigham
D E
DE
Department of Nutrition, College of Health and Human Development, Pennsylvania State University, University Park 16802.
Beard
J L
JL
Krimmel
R S
RS
Kenney
W L
WL
D000293:Adolescent; D000328:Adult; D000747:Anemia, Hypochromic / Q000188:drug therapy* / Q000517:prevention & control; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D002149:Energy Intake; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005293:Ferritins / Q000097:blood; D005296:Ferrous Compounds / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007501:Iron / Q000097:blood*; D008137:Longitudinal Studies; D010809:Physical Fitness / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D015430:Weight Gain
D003692:Delayed-Action Preparations; D005296:Ferrous Compounds; D006454:Hemoglobins; C020748:ferrous sulfate; D005293:Ferritins; D007501:Iron