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 .
Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial
Abstract Objective To determine the subjective response to iron therapy in non-anaemic women with unexplained fatigue . Design Double blind r and omised placebo controlled trial . Setting Academic primary care centre and eight general practice s in western Switzerl and . Participants 144 women aged 18 to 55 , assigned to either oral ferrous sulphate ( 80 mg/day of elemental iron daily ; n=75 ) or placebo ( n=69 ) for four weeks . Main outcome measures Level of fatigue , measured by a 10 point visual analogue scale . Results 136 ( 94 % ) women completed the study . Most had a low serum ferritin concentration ; ≤ 20 μg/l in 69 ( 51 % ) women . Mean age , haemoglobin concentration , serum ferritin concentration , level of fatigue , depression , and anxiety were similar in both groups at baseline . Both groups were also similar for compliance and dropout rates . The level of fatigue after one month decreased by −1.82/6.37 points ( 29 % ) in the iron group compared with −0.85/6.46 points ( 13 % ) in the placebo group ( difference 0.95 points , 95 % confidence interval 0.32 to 1.62 ; P=0.004 ) . Subgroups analysis showed that only women with ferritin concentrations ≤ 50 μg/l improved with oral supplementation . Conclusion Non-anaemic women with unexplained fatigue may benefit from iron supplementation . The effect may be restricted to women with low or borderline serum ferritin concentrations
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 .