Fatigue can be caused by an array of conditions.What is true for iron as supplement, should be taken as guideline for other (mineral or vitamin) supplements as well: Low doses may be OK, but high doses of (some) supplements can harm you – and any supplement might mainly give you expensive urine.
Iron deficiency is a common cause, though whether iron supplements offer benefit in the absence of anemia remains to be established.
Children and women, particularly pregnant women, need adequate iron in their diet.
While low-dose supplements are considered safe and may be helpful in meeting daily requirements, specific supplementation isn’t necessary or advisable in the absence of a clear deficiency.
And just because it’s a supplement doesn’t mean it can’t be harmful.
Iron supplements can be toxic in children, and should be stored like any other potential poison.
And personally, my advise to increase iron is:
- Ditch cereal grains
(see Loren Cordain' Cereal Grains: Humanity's Double-Edged Sword for details how grains hinder mineral absorption)
- And eat more beef