Iron (Elemental)
Supplement primarily when deficiency is confirmed; overdoses can be dangerous.
By Suplagen Team · Updated
What it is
Iron is essential for hemoglobin and oxygen transport. Supplementation is most appropriate with confirmed deficiency or clinician-directed need.
How it works
Supports hemoglobin/myoglobin; excess supplemental iron causes GI injury and oxidative stress.
What the evidence says
Strong for treating iron deficiency; unnecessary supplementation adds risk without benefit.
How much to take
The catalog range is 18 to 45 mg of elemental iron daily, and 45 mg is the ceiling for unsupervised use. Iron is the supplement where testing first is a rule, not a suggestion: strong evidence for correcting deficiency, and risk without benefit when you aren't deficient.
Therapeutic dosing for a diagnosed deficiency may exceed the ceiling under supervision. That's a doctor's call, made on ferritin and iron studies, and reassessed periodically.
When and how to take it
Morning, away from calcium, magnesium, zinc, and fiber, all of which blunt absorption. If it upsets your stomach, a small meal is fine; keep the minerals out of it.
Vitamin C is the one companion that helps. Take them together.
Who should skip it
Hemochromatosis and other iron overload disorders rule it out completely. Levothyroxine is a high-severity interaction: iron blocks its absorption, so keep them well apart. Proton pump inhibitors are moderate, since they reduce iron absorption. Pregnancy is listed as safe, and pregnancy dosing is its own conversation with a clinician.
Safety Notes
- UL is 45 mg/day for adults; therapeutic deficiency dosing may exceed UL under supervision.
- Use caution with: hemochromatosis, iron overload disorders.
- levothyroxine: Reduces absorption/effect; separate by ~4h.
- proton pump inhibitors: May reduce absorption and blunt response in deficiency.
Timing With Other Supplements
- Calcium (Supplemental): Can reduce iron absorption; separate ~2h.
Common questions
How much iron should I take for deficiency?
18 to 45 mg elemental daily is the catalog range, but deficiency dosing belongs to your doctor, based on ferritin and iron studies. Don't self-dose past 45 mg.
Should I take iron with or without food?
Without, for best absorption, unless it upsets your stomach. Then a small meal is fine, as long as it has no dairy, fiber supplements, or other minerals in it.
How far apart should iron and thyroid medication be?
Well apart: at least 2 hours, and ideally more. Iron blocks levothyroxine absorption, and the catalog grades the interaction high severity. Take the thyroid medication first thing, as prescribed, and the iron later.