Abstracted by Greg Arnold, DC, CSCS, July 30, 2012, from “Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial” published online July 9, 2012 in the Canadian Medical Association Journal. Posted July 31, 2012. r/ar
It is estimated that more than 1 in 4 patients make visits to their primary care doctors (27%) due in some part to fatigue (1). Fatigue has been shown to have a “substantial impact” on both personal and work productivity (2). Patients with unexplained fatigue may have an iron deficiency (3), as research has documented improvement in fatigue following iron supplementation, especially in women without any signs of anemia but with unexplained fatigue (4).
Now a new study (5) has continued to find iron supplementation to benefit unexplained fatigue. In the study, researchers analyzed 198 French women aged 18–53 years complaining of “considerable fatigue” (greater than 6 on a 1–10 Likert scale (6)), who had levels of a type of iron called ferritin below 50 micrograms/Liter but were not diagnosed with anemia as their hemoglobin levels were greater than 12.0 grams/deciliter. These women received either iron supplementation (oral ferrous sulfate = 80 mg of elemental iron daily = 102 patients) or placebo (96 patients) for 12 weeks. The researchers measured fatigue with the Current and Past Psychological Scale that measures fatigue on a scale of 0 to 40 points (7). They also obtained blood samples before the study began and at 6 and 12 weeks.
By the end of the study, those in the iron supplementation group had a 40% greater decrease in the Current and Past Psychological scale compared to the placebo group (12.2 vs. 8.7-point decrease, p = 0.02). This was thought to be due to iron supplementation helping increase hemoglobin by 0.28 grams/deciliter versus 0.05 g/dL decrease in the placebo group (p = 0.002) and increase ferritin 11.6 micrograms/Liter compared to a 0.2 micrograms/L increase in the placebo group (p < 0.001). However, there were no significant effects on quality of life (p = 0.2), depression (p = 0.97) or anxiety (p = 0.5).
For the researchers, “Iron deficiency may be an under-recognized cause of fatigue in women of child-bearing age” and that “Iron supplementation should be considered for women with unexplained fatigue who have ferritin levels below 50 μg/L.” Checking on body levels before supplementation can avoid an iron overload.
- Ridsdale L, Evans A, Jerrett W, et al. Patients with fatigue in general practice: a prospective study. BMJ 1993;307:103-6.
- McCrone P. The economic cost of chronic fatigue and chronic fatigue syndrome in UK primary care. Psychol Med 2003 Feb;33(2):253-61.
- Patterson AJ, Brown WJ, Powers JR, et al. Iron deficiency, general health and fatigue: results from the Australian Longitudinal Study on Women’s Health. Qual Life Res 2000;9:491-7.
- Verdon F, Burnand B, Fallab Stubi CL, et al. Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomized placebo controlled trial. BMJ 2003;326:1124-6.
- Vaucher P. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ 2012 Jul 9. [Epub ahead of print]
- Brunier G. A comparison of two methods of measuring fatigue in patients on chronic haemodialysis: visual analogue vs Likert scale. Int J Nurs Stud 1996 Jun;33(3):338-48.
- Pichot P, Brun JP. Brief self-evaluation questionnaire for depressive, asthenic and anxious dimensions. Ann Med Psychol (Paris) 1984; 142:862-5.