In IDNA adults  , iron supplementation is associated with reduced subjective measures of fatigue but not with objective improvements in physical capacity .
OBJECTIVE Iron supplementation in iron-deficiency anaemia is st and ard practice , but the benefits of iron supplementation in iron-deficient non-anaemic ( IDNA ) individuals remains controversial .
Our objective is to identify the effects of iron therapy on fatigue and physical capacity in IDNA adults .
Effects of iron supplementation in female athletes with low serum ferritin concentration.
Low serum ferritin concentrations are commonly found in female athletes . By study ing the effects of an 8-week iron or placebo supplementation in 31 female athletes ( aged 17 - 31 years ) , with an initial serum ferritin concentration less than or equal to 25 micrograms/l and blood hemoglobin 120 g/l , we investigated whether low serum ferritin values hinder aerobic performance . Serum ferritin concentration increased from 14 ( 25th and 75th percentile : 11 , 21 ) to 26 ( 18 , 36 ) micrograms/l in the iron-supplemented group , but remained at a low 11 ( 9 , 17 ) micrograms/l 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/l and 128 ( 126 , 134 ) g/l in the placebo group ( group difference : p = 0.001 ) . Iron supplementation did not affect blood lactate concentration or VO2max during an incremental ergometer test . Hence , aerobic performance was not impaired in nonanemic female athletes with serum ferritin 25 micrograms/l
In IDNA adults  , iron supplementation is associated with reduced subjective measures of fatigue but not with objective improvements in physical capacity .
OBJECTIVE Iron supplementation in iron-deficiency anaemia is st and ard practice , but the benefits of iron supplementation in iron-deficient non-anaemic ( IDNA ) individuals remains controversial .
Our objective is to identify the effects of iron therapy on fatigue and physical capacity in IDNA adults .