Iron supplements can halve fatigue levels in non-anaemic women with unexplained tiredness and low ferritin levels, concludes a new study.
Researchers in Switzerland recruited 198 women from GP practices in France aged between 18 and 50 years who were menstruating.
All the women had to report a fatigue rating of over six out of 10 on a Likert scale that had no obvious clinical cause, and were required to have a low or borderline ferritin level – defined as less than 50 micrograms/l.
Each woman was randomised to receive either oral iron or a placebo that was to be taken before or after meals for a period of 12 weeks. Fatigue was assessed at baseline and after 12 weeks using the validated Current and Past Psychological Scale. Blood samples were also analysed seven days prior to the study, at six weeks and again at 12 weeks.
At 12 weeks, the researchers found patients receiving the iron supplementation had a 3.5 point improvement in their fatigue scores, compared with controls.
This corresponded to a 48% decrease in fatigue for the group taking iron supplements, compared with a 29% decrease for the placebo patients, and this difference was statistically significant.
After six weeks of iron, there were significant improvements in ferritin (an increase of 6.8micrograms/l) and haemoglobin (0.3g/dl), compared with the placebo group.
The researchers from the University of Lausanne concluded: ‘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.’