Jul 19 2012
By Caroline Price
Iron deficiency may be an under-recognized cause of fatigue in women, say investigators who report that iron supplementation reduced symptoms of fatigue in women who were not anemic but had low ferritin levels.
In a randomized controlled trial, women who took iron supplements for 12 weeks experienced an almost 50% reduction in fatigue levels, a 19% greater reduction than with placebo, report Bernard Favrat (University of Lausanne, Switzerland) and team.
The study included 198 adult menstruating women aged 18-53 years with considerable fatigue (>6 on a 1-10 Likert scale) without any obvious clinical cause, who were not anemic (hemoglobin levels≥12.0 g/dL), but had low or borderline ferritin levels (<50 µg/L).
Mean score on the Current and Past Psychological Scale for fatigue reduced by 47.7% among 102 participants who took an oral ferrous sulfate supplement (80 mg elemental iron daily) for 12 weeks, compared with 28.8% among 96 participants who took placebo.
This equated to a significant, 18.9% between-group difference, the authors note in the Canadian Medical Association Journal.
However, iron supplementation had no effect on measures of quality of life, depression, or anxiety.
Favrat and team report that the iron supplementation improved hemoglobin and iron stores as early as 6 weeks into treatment. By 12 weeks, the iron supplement had increased hemoglobin by 0.32 g/dL and ferritin by 11.4 µg/L, and decreased soluble transferring receptor levels by 0.54 mg/L, when compared with placebo.
Further analysis revealed that the effects of iron supplementation on fatigue, quality of life, and hemoglobin were independent of women's baseline ferritin and transferrin saturation levels. Women whose initial hemoglobin was below 13.0 g/dL had a greater hemoglobin response to iron supplementation than those with higher baseline hemoglobin, but did not derive any further treatment benefits.
"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," reason the authors.
They conclude: "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 healthcare resources, including inappropriate pharmacologic treatments."
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