Iron is a mineral your body uses to make haemoglobin, the protein in red blood cells that carries oxygen from the lungs to the tissues1.
Iron is part of haemoglobin, which moves oxygen from the lungs to the tissues1.
As part of myoglobin, iron supplies oxygen that supports muscle metabolism1.
Iron is needed for physical growth and neurological development1.
Iron supports normal cell functioning and the making of some hormones1.
| Food and serving | Amount |
|---|---|
| White beans, canned, 1 cup | 8 mg |
| Lentils, boiled, ½ cup | 3 mg |
| Spinach, boiled, ½ cup | 3 mg |
| Tofu, firm, ½ cup | 3 mg |
| Chickpeas, boiled, ½ cup | 2 mg |
| Dark chocolate (45–69% cacao), 1 oz | 2 mg |
| Food and serving | Amount |
|---|---|
| Oysters, cooked, 3 oz | 8 mg |
| Beef liver, pan fried, 3 oz | 5 mg |
| Sardines, canned in oil, 3 oz | 2 mg |
| Beef, braised bottom round, 3 oz | 2 mg |
Plant (non-heme) iron is absorbed less well, and eating it with vitamin C foods such as citrus, tomatoes or potatoes can help3. Amounts per serving from1.
The same reference table draws the reference lines on your charts in Ayuvo. Needs differ in pregnancy and breastfeeding, which are not covered here.
| Age | Women | Men | Upper limit |
|---|---|---|---|
| 19–30 | 18 mg | 8 mg | 45 mg |
| 31–50 | 18 mg | 8 mg | 45 mg |
| 51–70 | 8 mg | 8 mg | 45 mg |
| 71+ | 8 mg | 8 mg | 45 mg |
RDA (Recommended Dietary Allowance) is the daily amount that meets the needs of nearly all healthy people. Per day, for adults1.
Upper limit (UL) is the most per day that is unlikely to cause harm. Applies to food, drinks and supplements combined.
Signs like these have many possible causes. They are a reason to talk to a clinician, not to self-treat.
When iron stores run out, haemoglobin falls and iron-deficiency anaemia can develop1.
Iron overload from food is unlikely with normal gut function, but high-dose supplements can cause side effects1.
Serum ferritin reflects iron stores and drops early in iron depletion; inflammation can raise it, so haemoglobin and transferrin saturation are often checked too1.
| Ferritin | What it may mean |
|---|---|
| Below 30 µg/L | Suggests iron deficiency |
| Below 10 µg/L | Suggests iron-deficiency anaemia |
Labs use different units and ranges. Your clinician reads a result alongside your history and other tests.
Iron supplements mostly use ferrous or ferric salts, and ferrous forms are absorbed better than ferric ones1.
A common form that is about 20% elemental iron by weight1.
About 33% elemental iron by weight1.
About 12% elemental iron by weight1.
Ferric forms are less soluble, so they are less bioavailable than ferrous iron1.
These and heme iron polypeptides might cause fewer stomach side effects than iron salts1.
Supplements can interact with medicines. Talk to a clinician or pharmacist before you start one, especially at high doses.
Heme iron is found in meat, poultry and seafood and is absorbed more easily. Non-heme iron comes from plants, beans and fortified grains, and how much you absorb depends more on what you eat with it, such as vitamin C.
Yes. Because plant iron is absorbed less well, intake recommendations for people on vegetarian diets are higher than for people who eat meat. Pairing plant iron with vitamin C foods can help.
Often, yes. Serum ferritin falls in the first stage of iron depletion, so it can show low stores before haemoglobin drops. Inflammation can raise ferritin, so it is usually read alongside other results.
Ayuvo charts iron by day, week, month and year, with the reference lines from this page, personalised by age and sex where they differ. Supplements you log in Medications count too. Free, with no account.
Or read the code: Ayuvo is open source
Facts on this page come from these sources, checked on the dates shown. Intake numbers come from Ayuvo's shared reference table, which cites the sources marked for them.
General information, not medical advice. This guide is for healthy adults and does not cover pregnancy, breastfeeding, children or medical conditions. It cannot diagnose or treat anything. Talk to a clinician before starting high-dose supplements, or if you think you may have too little or too much of a nutrient. Spotted an error? Email us.