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Iron: the daily reference intake

The premenopausal female reference intake, 16 mg a day, is the highest adult figure in the whole EFSA table and nearly half as much again as the male 11 mg. After the menopause it drops straight back to 11 mg. This is the single largest sex difference in the reference intakes.

These are published population reference values, not a diagnosis and not a prescription. A reference intake describes what covers a healthy group; it cannot tell you your own status, and no page can. Pregnancy, chronic illness, medicines and malabsorption all change the picture — take those questions to a doctor, midwife, pharmacist or dietitian.

Iron by age, sex and life stage

The 11 to 14 year band is deliberately absent: EFSA splits at 12 years and the value for girls depends on whether menstruation has started, so a single row for 11 to 14 would be misleading.

One number, driven by blood loss

Iron is recycled almost perfectly by the body; the ordinary daily loss is tiny. What makes the female requirement high is menstruation, and the distribution of menstrual loss is skewed — most women lose a moderate amount, a minority lose a great deal. EFSA sets the Population Reference Intake at 16 mg to cover 95 per cent of premenopausal women, well above the Average Requirement.

The corollary is that the number falls the moment menstruation stops. Postmenopausal women sit at 11 mg, the same as men. A woman who keeps taking a supplement chosen for the premenopausal figure is no longer matching her own requirement.

Why pregnancy does not raise the reference intake

This surprises almost everyone. EFSA sets the same 16 mg a day for pregnancy as for premenopausal women, because menstruation stops and iron absorption rises substantially over the course of the pregnancy, which together offset the iron transferred to the fetus and the expansion of maternal blood volume.

That is a statement about the population reference value, not about you. Iron deficiency anaemia in pregnancy is common and is managed with measured ferritin and haemoglobin, and antenatal care in the Baltic and Nordic countries screens for it. A pregnancy supplement is a clinical decision, not a table lookup.

Haem and non-haem: the same milligram is not the same milligram

Iron in meat, fish and poultry is largely haem iron and is absorbed several times more efficiently than the non-haem iron in plants, eggs and dairy. Non-haem absorption is also strongly modified by what is on the plate with it: vitamin C raises it substantially, while the phytate in wholegrains and legumes, the polyphenols in tea and coffee, and large calcium doses all lower it.

That is why a vegetarian or vegan diet is usually planned around iron rather than around milligrams: pairing beans, lentils, wholegrain rye or pumpkin seeds with a source of vitamin C, and keeping tea and coffee away from the meal itself, changes how much of the same food is absorbed.

Reading the food table honestly

The amounts below are total iron per portion from the USDA composition data. They do not distinguish haem from non-haem, and no widely available food table does that reliably. Treat plant entries as delivering less than the number suggests and animal entries as delivering more.

The upper level

EFSA has not set a tolerable upper intake level for iron. Iron supplements taken without a measured deficiency are not harmless: iron overload is a real condition, and accidental iron overdose is one of the commonest serious poisonings in small children.

Ordinary food against the 16 mg reference intake for women 19-50

Top of this list: Soybeans, 7.71 mg in a 150 g serving (a portion, cooked) — 48% of the 16 mg reference intake for women 19-50. It would take about 3 of those to cover a full day from that one food, which is why a real diet spreads it across several rows.

Portion sizes are ordinary household servings chosen for this table, not official reference portions, and the shortlist is an editorial one: everyday foods eaten in this region rather than the highest per-100 g entries in the database. A raw per-100 g ranking would be topped by dried herbs, drink powders and fortified breakfast cereals, which answers a different question. The composition data is American, so where US fortification practice differs from European practice the row carries a dagger and the reason. For the full per-100 g ranking of a nutrient, the food-data section of this site publishes one.

Iron for one group at a time

For the full ranking of every food in the database by iron per 100 g, see foods highest in iron.

Sources: EFSA Dietary Reference Values · Regulation (EU) No 1169/2011, Annex XIII · USDA FoodData Central SR Legacy (food composition) · EFSA scientific opinion on dietary reference values for iron (2015) · Regulation (EU) No 1169/2011, Annex XIII · checked 2026-09-06

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