Iron Usage

The most obvious use of iron supplements is to treat iron deficiency. Severe iron deficiency causes anemia, which in turn causes many symptoms. Iron deficiency too slight to cause anemia may impair health as well. Several, though not all, double-blind trials suggest that mild iron deficiency might impair sports performance . ¹ In addition, a double-blind, placebo-controlled study of 144 women with unexplained fatigue who also had low or borderline-low levels of ferritin (a measure of stored iron) found that iron supplement enhanced energy and wellbeing. ² Another study found that iron supplements improved mental function in women who were iron deficient. ³ However, don't take iron just because you feel tired. Make sure to get tested to see whether you are indeed deficient. With iron, more is definitely notbetter. (See Safety Issues .)

Excessively heavy menstruation (menorrhagia) can certainly cause iron loss, and thereby may warrant iron supplements. Interestingly, a small double-blind trial found evidence that iron supplements might actually help reduce menstrual bleeding in women with menorrhagia who are also iron deficient. ⁴ A study of 71 HIV-positive children noted a high rate of iron deficiency. ⁵ One observational study of 296 men with HIV infection linked high intake of iron to a decreased risk of AIDS 6 years later. ⁶ Individuals taking drugs in the ACE inhibitor family frequently develop a dry cough as a side effect. One study suggests that iron supplementation can alleviate this symptom. ⁷ (However, iron can interfere with ACE inhibitor absorption, so it should be taken at a different time of day.)

Pregnant women commonly develop iron deficiency anemia. Iron supplements, however, can be hard on the stomach, thereby aggravating morning sickness . One study found evidence that a fairly low supplemental dose of iron—20 mg daily—is very nearly as effective for treating anemia of pregnancy as 40 mg or even 80 mg daily and is less likely to cause gastrointestinal side effects. ⁸ Iron has been suggested as a treatment for attention deficit hyperactivity disorder , but there is only preliminary evidence that it may effective in hyperactive children with low iron levels as indicated by ferritin levels. ⁹ Preliminary studies have linked low iron levels to restless legs syndrome . ^{10 11} However, a small double-blind study found no benefit when iron supplements were given to healthy people (eg, those who were not iron deficient) ¹² One study tested whether supplemental iron could increase rate of saliva flow, but it failed to find benefit. ¹³