It is known that Fe deficiency has a negative impact on cognitive function in children by
altering brain energy metabolism and neurotransmitter function. It is unclear whether Fe
deficiency has detrimental effects on cognition, mental health and fatigue in women of
childbearing age. Our aim was to systematically review the literature to determine whether
Fe deficiency in women of childbearing age affects cognition, mental health and fatigue,
and whether a change in Fe status results in improvements in cognition, mental health and
fatigue. Studies using Fe supplement interventions were reviewed to examine the effect of
Fe deficiency in women of childbearing age (13–45 years) on their cognition, mental health
and fatigue. English-language articles ranging from the earliest record to the year 2011
were sourced. The quality of retrieved articles was assessed and the Fe pathology,
cognitive, mental health and fatigue data were extracted. Means and standard deviations
from cognitive test data were included in meta-analyses of combined effects. Of the 1348
studies identified, ten were included in the review. Three studies showed poorer cognition
and mental health scores and increased fatigue with Fe deficiency at baseline. Seven
studies reported an improvement in cognitive test scores after Fe treatment. Results of
three of these studies were included in meta-analyses of the effect of Fe supplement
intervention on cognition. The results of the meta-analyses showed a significant
improvement in Arithmetic scores after treatment (P < 0·01), but
no effect on Digit Symbol, Digit Span or Block Design. While an improvement in cognition
after Fe treatment was seen in seven out of ten studies, the evidence base is limited by
poor study quality and heterogeneity across studies. Additional high-quality studies using
consistent measures are warranted.