Iron Intake Checker
Heavy or irregular periods through perimenopause are the leading driver of iron deficiency in women — and the fatigue gets blamed on hormones. This turns your age, cycle and diet into a daily target, plus the absorption rules that decide whether the number on your plate actually lands in your blood.
Daily iron target
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Where that number lives — biggest iron doses per serving
| Food | Iron per serving | Serving | Per 100 g |
|---|---|---|---|
| Rice Krispies | 11.2 mg | 1½ cups | 28.0 mg / 100 g |
| Mussels (cooked) | 10.1 mg | One cup | 6.7 mg / 100 g |
| Cheerios (plain) | 8.1 mg | One cup | 28.9 mg / 100 g |
| Whopper | 8.1 mg | One burger | 3.0 mg / 100 g |
| Oysters (cooked) | 7.7 mg | Six oysters | 9.2 mg / 100 g |
| Lentils (cooked) | 6.6 mg | One cup | 3.3 mg / 100 g |
| Sorghum (cooked) | 6.1 mg | One cup | 3.4 mg / 100 g |
| Corn flakes | 5.4 mg | One cup | 19.4 mg / 100 g |
| Kidney beans (cooked) | 5.2 mg | One cup | 2.9 mg / 100 g |
| Amaranth (cooked) | 5.2 mg | One cup | 2.1 mg / 100 g |
| Teff (cooked) | 5.1 mg | One cup | 2.0 mg / 100 g |
| Sunchokes (Jerusalem artichoke) | 5.1 mg | One cup | 3.4 mg / 100 g |
Common questions
How much iron do women need per day?
The RDA is 18 mg for women aged 19–50 — more than double men's 8 mg, because of menstrual losses. After menopause it drops to 8 mg. Heavy periods can push real needs above the RDA; a ferritin blood test is the honest check, not a calculator.
Why do vegetarians need more iron?
Plant (non-heme) iron absorbs at roughly half the rate of the heme iron in meat. The Institute of Medicine's rule of thumb: vegetarians need about 1.8× the standard target.
Does coffee really block iron absorption?
Yes — polyphenols in coffee and tea can cut non-heme iron absorption by up to 60–90% when drunk with a meal. The fix is timing, not quitting: keep the cup an hour away from iron-rich meals, and pair iron with vitamin C.
Method
Targets follow the National Academies (IOM) RDAs: 18 mg for women 19–50 with periods, 8 mg for men and for women after menopause; plant-based diets multiply the target by 1.8 per the IOM's absorption adjustment. Heavy bleeding doesn't get a universally agreed multiplier — the guidance is a ferritin test, which this page says out loud. Absorption rules: heme iron (meat, fish) absorbs ~15–35%; non-heme ~2–20%, boosted by vitamin C, cut by coffee/tea polyphenols and by calcium with the meal.
The ranking behind the table: iron rich foods, per 100 g and per 100 kcal · Coffee timing: the cutoff calculator · Where are you in perimenopause?