The women in the new study, published in the CMAJ, did not have anemia, but were considered to have borderline levels of ferretin.
A daily dose of 80 milligrams of elemental iron in the form of ferrous sulfate was associated with a decrease in fatigue stores of 48%, compared to a decrease of 29% in the placebo group, according to researchers from the University of Geneva, Switzerland, and the French National College of General Practitioners.
“Iron deficiency may be an under-recognized cause of fatigue in women of child-bearing age. If fatigue is not due to secondary causes, the identification of iron deficiency as a potential cause may prevent inappropriate attribution of symptoms to putative emotional causes or life stressors, thereby reducing the unnecessary use of health care resources, including inappropriate pharmacologic treatments.”
The study is amongst the first to evaluate the effects of iron supplementation in non-anemic menstruating women with fatigue.
The European researchers recruited 198 women from 44 primary care physicians in France for their multi-center, parallel, randomized controlled, closed-label, observer-blinded trial. Women received either oral ferrous sulfate supplements or placebo for 12 weeks.
Results showed that fatigue decreased by 48% in the supplement group, and by 29% in the placebo group.
In addition, the iron supplements increased hemoglobin levels and ferritin levels, said the researchers.
“We found that iron supplementation for 12 weeks decreased fatigue by almost 50% from baseline, a significant difference of 19% compared with placebo, in menstruating iron-deficient non-anemic women with unexplained fatigue and ferritin levels below 50 μg/L,” they wrote.
“For women with unexplained prolonged fatigue, iron deficiency should be considered when ferritin values are below 50 μg/L, even when hemoglobin values are above 12.0 g/dL.
“Biological markers can be tested at six weeks to confirm iron deficiency. Recent advances in neuroscience and imagery enable iron load to be observed in the central nervous system, which should make it possible to investigate brain iron deficiency independently of iron-deficiency anemia.”
Published online ahead of print, doi: 10.1503/cmaj.110950
“Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial”
Authors: Vaucher P, Druais PL, Waldvogel S, Favrat B.