Approximate dose-response bands. Individual response varies — these are starting points, not prescriptions.
Iron-deficiency anemia: fatigue, pale skin, brittle nails. More common in menstruating people.
Below target — pair with vitamin C, avoid taking with coffee/tea/calcium.
DV (18 mg) met. Supports hemoglobin, oxygen transport, energy metabolism.
Used during iron repletion. Get ferritin tested before supplementing high doses long-term.
Iron overload risk — especially for men and post-menopausal people.
Above UL (45 mg) — GI side effects and oxidative stress. Cut back unless under clinical care.
You're at 0% of your iron target. The biggest single-serving sources to top it off:
Central to oxygen transport (hemoglobin), oxygen storage (myoglobin), and electron transfer (cytochromes, iron-sulfur clusters). Tightly regulated because both deficiency (anemia, fatigue, cognitive impairment) and excess (Fenton oxidation, organ damage) carry real harm. Heme iron from animal foods is far better absorbed than non-heme iron from plants.
Heme iron is absorbed intact via heme carrier protein 1 (HCP1) at ~25% efficiency. Non-heme iron must be reduced from Fe3+ to Fe2+ by DCytb (reductase) and absorbed via DMT1 at ~5–10% efficiency, modulated by current iron status. Hepcidin (liver-secreted) is the master regulator: high stores → high hepcidin → reduced absorption and reduced macrophage iron release.
Most common nutritional deficiency worldwide. Affects ~10% of premenopausal women in the developed world; higher in low-income countries. Diagnosed via ferritin (<30 ng/mL flags iron-deficient erythropoiesis even with normal hemoglobin).
Hereditary hemochromatosis (HFE gene) drives iron overload in ~1/200 Northern Europeans. Excess catalyses Fenton chemistry — generating hydroxyl radicals that damage liver, heart, pancreas, joints. Never supplement iron without documented deficiency.
Ferrous bisglycinate is the best-tolerated chelated form and well-absorbed at lower elemental doses. Ferrous sulfate is the cheapest and clinically validated but causes constipation and GI distress in many users. Take on an empty stomach with vitamin C; avoid taking with calcium, coffee, or tea. Alternate-day dosing achieves similar repletion with better tolerability.
Heme iron ~15–35% absorbed regardless of co-ingested foods. Non-heme iron 2–20%, strongly modulated by vitamin C (boosts 3–4×), phytate, polyphenols (tea, coffee), calcium (all inhibit). High-dose iron supplementation transiently elevates hepcidin for ~24 hours — alternate-day dosing increases fractional absorption.
Adequacy (not excess) is the longevity-relevant range. Higher serum ferritin in non-deficient adults correlates with insulin resistance, hepatic fat, and modest mortality increase — particularly in post-menopausal women and men who no longer lose iron monthly. Routine multivitamins for men should not contain iron unless documented need.
Hemoglobin, myoglobin, oxidative phosphorylation.
Forms with lower absorption: ferric oxide, elemental iron. Prefer better-absorbed forms when supplementing.
The mechanisms and systems this nutrient feeds. Click any to drill into what runs on it.
★ = load-bearing / primary cofactor. Track these in My Journey.
Whole foods that contribute meaningfully (≥10% DV per 100 g serving). Click any food to see its full nutrient profile and what else it brings to the table.
See all foods high in Iron, ranked →