This study assessed serum ferritin, hemoglobin, and hematocrit among 107 physically active young people 9 to 18 years of age. Tanner stage (TS) of puberty was assessed and subjects were categorized as prepubertal (TS 1), midpubertal (TS 2, 3, and 4, excluding menarcheal females) and going through their rapid growth phase, or late pubertal (TS 5 and menarcheal females) and having completed their rapid growth phase. Midpubertal females had a lower hematocrit than late pubertal females, but there were no significant differences in serum ferritin or hemoglobin between pubertal groups. Late pubertal males had hemoglobin and hematocrit values that were higher than among prepubertal males, but serum ferritin did not differ. At late puberty the males had significantly higher serum ferritin, hemoglobin, and hematocrit compared with late pubertal females, and females in late puberty were more likely to have marginal iron stores compared with males at the same stage of pubertal development. Midpubertal and late pubertal females reported a diet low in absorbed iron, which could contribute to their poorer iron status.
N.D. Willows, S.K. Grimston, D. Roberts, and D.J. Smith are with the Human Performance Laboratory, Faculty of Physical Education, University of Calgary. D.A. Hanley is with the Div. of Endocrinology & Metabolism, Faculty of Medicine, Univ. of Calgary, Calgary, AB, Canada T2N 1N4. Request reprints from D.A. Hanley.