Iron
Also known as Fe
Iron is an essential trace mineral central to hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the tissues. It also supports myoglobin, energy metabolism, and many enzymes. The body tightly regulates iron because it has no active way to excrete excess. Needs differ sharply by sex and life stage: menstruating women lose iron monthly and require far more than men, while pregnancy raises demand higher still.
The recommended intake sits at about 40% of the level considered the safe daily ceiling, leaving comfortable headroom.
Why it matters
What it does in your body
- Oxygen transport in blood via hemoglobin
- Oxygen storage in muscle via myoglobin
- Energy metabolism and electron transport
- Support for immune function
- Normal cognitive development
By age, sex, and life stage
How much you need
Iron uses an RDA for most groups (AI for infants 0 to 6 months). Menstruating women 19 to 50 need 18 mg, dropping to 8 mg at 51+ after menopause. Pregnancy raises the requirement to 27 mg. Teen girls 14 to 18 need 15 mg versus 11 mg for boys.
Recommended intake across life
in mg/dayBars scale to the highest recommendation shown. Where men and women differ, both values are listed.
Full reference table
| Life stage | Male | Female |
|---|---|---|
| Infants 0-6 mo | 0.27 (AI) | 0.27 (AI) |
| Infants 7-12 mo | 11 | 11 |
| Children 1-3 | 7 | 7 |
| Children 4-8 | 10 | 10 |
| Children 9-13 | 8 | 8 |
| Teens 14-18 | 11 | 15 |
| Adults 19-50 | 8 | 18 |
| Adults 51+ | 8 | 8 |
| Pregnancy | n/a | 27 |
| Lactation | n/a | 9 to 10 |
Values in mg/day. AI marks an Adequate Intake, used when there is not enough evidence for a formal recommendation.
What moves the number
What changes your needs
Age
Requirements rise from 7 mg in toddlers to 8 to 18 mg in adults, then settle at 8 mg for both sexes at 51+ years.
Sex
Menstruating women need 18 mg versus 8 mg for men because of monthly menstrual blood loss.
Body weight / size
Larger blood volume and greater muscle mass raise total iron needs, which is part of why male requirements track body size during growth.
Pregnancy and lactation
Pregnancy needs jump to 27 mg to build fetal and placental tissue and expand maternal blood volume; lactation drops back to 9 to 10 mg.
Diet type
Vegetarians may need up to 1.8 times more iron because non-heme iron from plants is less bioavailable than heme iron from meat.
Running low
Signs you might not get enough
Most at risk: Pregnant women, infants and young children, women with heavy menstrual bleeding, frequent blood donors, and people with cancer, gastrointestinal disorders, or heart failure are at greatest risk.
Too much
Can you get too much?
Accidental iron overdose from supplements is a leading cause of poisoning death in young children. People with hereditary hemochromatosis absorb excess iron and can develop organ damage even at normal intakes.
Where to get it
Best food sources
The bottom line
Iron needs are dominated by sex and life stage: menstruating women need more than twice what men do, and pregnancy more still. Heme iron from meat is absorbed far better than plant iron, so vegetarians should aim higher. Never take high-dose iron supplements without a confirmed deficiency, and keep them away from children.
Track iron automatically
Iron is one of the 92 nutrients Vora reads from a photo of your meal, so you can see where you stand without weighing or logging by hand.
Sources and method
The recommended intakes, upper limits, and food-source amounts on this page come from the primary references below. Numbers were checked against the current NIH Office of Dietary Supplements fact sheets and the Institute of Medicine (now the National Academies) Dietary Reference Intakes.
- NIH Office of Dietary Supplements, Iron Fact Sheet for Health Professionals
- Institute of Medicine (IOM/NASEM), Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
This page is for general education, not medical advice. Reference intakes are population averages for healthy people and do not replace guidance from your doctor or a registered dietitian, especially if you are pregnant, managing a health condition, or considering supplements.