The short answer
Heme iron, from meat, fish and shellfish, is absorbed easily and barely affected by tea or coffee. Non-heme iron, from plants, eggs and most supplements, has to be converted first, needs vitamin C and is easily blocked.
| Heme iron | Non-heme iron | |
|---|---|---|
| Found in | Meat, liver, fish, shellfish | Beans, lentils, grains, seeds, greens, eggs, most supplements |
| Absorbed | Easily, by its own route | Less, and it varies a lot with the meal |
| Helped by | Little: it gets in anyway | Vitamin C, carotenoids, a little meat or fish |
| Blocked by | Calcium | Calcium, tea, coffee, cocoa, phytates |
Getting more from plant iron
- Add a vitamin C food to the same plate: raw pepper, parsley, lemon, berries, kiwi.
- Add colour: sweet potato, carrot, tomato and pumpkin carry carotenoids that guard iron.
- Add a little meat or fish to beans and lentils. Heme iron helps plant iron in too.
- Soak beans and lentils, and choose sourdough, to cut phytates.
- Keep coffee, tea and dairy away from the meal.
- mg9Iron in 100 g of chicken liver, all of it heme
- mg3.3Iron in 100 g of cooked lentils, non-heme
Eggs carry non-heme iron and a yolk protein that holds back a little of it. Pair them with pepper, tomato or parsley and they work fine.
Questions
Is non-heme iron useless?
No. It is absorbed, just less well, and you can raise that a lot with vitamin C and by keeping blockers away. Many people get most of their iron from plants.
Are iron supplements heme or non-heme?
Most are non-heme, so the same rules apply: keep them away from coffee, tea and dairy. Heme iron supplements exist but are less common.
Sources
- 1.NIH Office of Dietary Supplements. Iron: fact sheet for health professionals
- 2.Harvard T.H. Chan School of Public Health. The Nutrition Source: Iron
- 3.Hallberg L. et al. Calcium: effect of different amounts on nonheme- and heme-iron absorption in humans. American Journal of Clinical Nutrition, 1991
- 4.The Iron Guide, part 4: Food that counts
This page has not been reviewed by a clinician yet. Read it as general education, and take your own results to your doctor.
Educational, not medical advice. ferritin.ai does not diagnose or treat any condition, and it never sets a dose. Talk to your doctor about your own results.