Iron deficiency in adolescent female athletes - is iron status affected by regular sporting activity?

OBJECTIVE To determine the prevalence of iron deficiency (ID) and iron deficiency anemia (IDA) among a group of female athletes and compare with an age-matched group of female nonathletes. To study lifestyle factors that could play a role in the development of ID and IDA and compare these factors between the groups. DESIGN A controlled clinical trial. SETTING A senior high school for athletes in Gothenburg, Sweden. PARTICIPANTS All female athletes at a senior high school for top-level athletes were offered to take part. Fifty-seven female athletes accepted to participate in the study. The control group consisted of a random sample of 130 age-matched nonathlete students; 92 accepted to participate in the study. INTERVENTION Intervention was not an actual part of this study but those with ID and IDA were treated with iron by the regular school doctor. MAIN OUTCOME MEASURES Iron deficiency anemia and ID were determined by levels of hemoglobin, serum iron, total iron-binding capacity, transferrin saturation, and serum ferritin. RESULTS The main result of the study is the finding that ID and IDA are common among young adolescent female athletes and that there was no difference between female athletes and nonathletes. In the athlete group, 30 of 57 individuals (52%) had ID compared with 43 of 92 individuals (48%) in the nonathlete group (P > 0.3). Comparisons of the 2 groups showed no significant difference in hemoglobin (P > 0.30). In total, we found that 5 of 57 athletes (8.6%) had IDA compared with 3 of 92 nonathletes (3.3%), the difference being not statistically significant (P = 0.24). CONCLUSIONS The main finding of this study is that ID and IDA are common among female adolescents but not more common among athletes than nonathletes. The results are despite factors that should favor a better iron status in the athlete group, such as better iron intake and less menstrual bleeding. Other factors that might have an impact on iron balance, must therefore be considered.