Effects of Iron Supplementation in Female Athletes with Low Serum Ferritin Concentration

Abstract

Low serum ferritin concentrations are commonly found in female athletes. By studying the effects of an 8-week iron or placebo supplementation in 31 female athletes (aged 17-31 years), with an initial serum ferritin concentration ≤ 25µg/1 and blood hemoglobin 120 g/1, we investigated whether low serum ferritin values hinder aerobic Performance. Serum ferritin concentration in-creased from 14 (25th and 75th percentile: 11,21) to 26 (18, 36) µg/1 in the iron-supplemented group, but remained at a low 11 (9, 17) µg/1 in the placebo group (group difference after supplementation: p = 0.001). Before supplementation, blood hemoglobin concentration was not different in the two groups. After supplementation, however, the concentration in the iron group was 139 (135, 144) g/1 and 128 (126, 134) g/1 in the placebo group (group difference: p = 0.001). Iron supplementation did not affect blood lactate concentration or V̇O₂max during an incremental ergometer test. Hence, aerobic Performance was not impaired in nonanemic female athletes with serum ferritin 25 µg/1.