Iron
Carries oxygen in haemoglobin and muscle; needed for energy and brain function.
If you are short of it
Possible signs
- Tiredness, low energy
- Pale skin
- Breathless on effort
- Hair thinning or loss
- Brittle or ridged nails
- Feeling cold, slowed down
- Restless legs, poor sleep
- Cracks at the corners of the mouth
- Palpitations (fast heartbeat)
- Poor memory or concentration
- Frequent infections
These signs are common and have many other causes. They are clues, not proof; a blood test and a doctor can tell.
Who is more at risk
Women with periods (especially heavy), pregnancy, babies and toddlers, teenage girls, vegetarians, frequent blood donors, coeliac disease, stomach or bowel bleeding, weight-loss surgery.
Foods rich in Iron
| Food | Serving | Amount | women 19–50 | men 19–50 |
|---|---|---|---|---|
| Lentils | 1 cup cooked | 6.6 NIH | 37% | 83% |
| Beef liver | 85 g cooked | 5.2 NIH | 29% | 65% |
| Chickpeas | 1 cup cooked | 4.7 NIH | 26% | 59% |
| Fortified breakfast cereal | 1 bowl (30 g) — check the label | 4.5 | 25% | 56% |
| Black-eyed peas (lobia) | 1 cup cooked | 4.3 | 24% | 54% |
| Kidney or white beans | 1 cup cooked | 4 NIH | 22% | 50% |
| Tofu (firm, calcium-set) | ½ cup (125 g) | 3.4 NIH | 19% | 43% |
| Dark chocolate (70% or more) | 30 g, about 3 squares | 3.4 | 19% | 43% |
| Spinach (cooked) | ½ cup (90 g) | 3.2 NIH | 18% | 40% |
| Quinoa | 1 cup cooked | 2.8 | 16% | 35% |
| Mung beans | 1 cup cooked | 2.8 | 16% | 35% |
| Sardines (canned, with bones) | 1 can (90 g drained) | 2.7 NIH | 15% | 34% |
| Beef (lean) | 100 g cooked | 2.7 NIH | 15% | 34% |
| Molokhia (cooked) | 1 cup (90 g leaves) | 2.7 | 15% | 34% |
Unit: mg. Share of the daily amount. Values marked NIH were checked against the food tables of the NIH Office of Dietary Supplements; the others are approximate and unchecked. Real foods vary with variety, brand, soil and cooking.
As a supplement
Ferrous sulphate, fumarate or gluconate, or gentler bisglycinate. Take with vitamin C and away from tea, coffee and milk; alternate-day dosing can absorb better with fewer stomach upsets.
Too much
Too much iron is dangerous: supplement only after a blood test shows low ferritin, unless prescribed. Iron tablets are a leading cause of poisoning in young children — keep them locked away. Constipation and dark stools are common.
How much you need each day
| Group | Recommended | Upper limit |
|---|---|---|
| Infants 0–6 months | 0.27 | 40 |
| Infants 7–12 months | 11 | 40 |
| Children 1–3 years | 7 | 40 |
| Children 4–8 years | 10 | 40 |
| Children 9–13 years | 8 | 40 |
| Boys 14–18 years | 11 | 45 |
| Girls 14–18 years | 15 | 45 |
| Men 19–30 years | 8 | 45 |
| Women 19–30 years | 18 | 45 |
| Men 31–50 years | 8 | 45 |
| Women 31–50 years | 18 | 45 |
| Men 51–70 years | 8 | 45 |
| Women 51–70 years | 8 | 45 |
| Men over 70 | 8 | 45 |
| Women over 70 | 8 | 45 |
| Pregnant 14–18 years | 27 | 45 |
| Pregnant 19–30 years | 27 | 45 |
| Pregnant 31–50 years | 27 | 45 |
| Breastfeeding 14–18 years | 10 | 45 |
| Breastfeeding 19–30 years | 9 | 45 |
| Breastfeeding 31–50 years | 9 | 45 |
Unit: mg. US/Canada Dietary Reference Intakes (National Academies), as summarised by the NIH Office of Dietary Supplements. Other countries’ values differ slightly. These are amounts for healthy people, not treatment doses.
Interactions
Avoid together · Calcium
Calcium reduces iron absorption. Take iron and calcium (also dairy, tea, coffee) at least 2 hours apart.
Take care · Zinc
High-dose iron and zinc taken together compete for absorption. If you take both as separate pills, space them out.
Works together · Vitamin C
Vitamin C taken with iron-rich plant foods or an iron tablet increases iron absorption.
Works together · Vitamin A
Vitamin A helps release iron from stores. Low vitamin A can make anaemia resist iron treatment.
Works together · Copper
Copper is needed to use iron: copper deficiency gives anaemia that does not respond to iron.
Medicines and habits to mention to your doctor
Levothyroxine (thyroid hormone)
Take it alone on an empty stomach and wait about 4 hours before calcium, iron or magnesium supplements.
Tetracycline, doxycycline, ciprofloxacin, levofloxacin
Minerals bind these antibiotics. Usually take the antibiotic 2 hours before or 4–6 hours after the supplement or dairy; check the leaflet.
Acid reducers (omeprazole, esomeprazole, famotidine)
Long-term use lowers absorption of B12, iron, magnesium and calcium carbonate. Calcium citrate is a better choice; ask about monitoring.
Osteoporosis tablets (alendronate and similar)
Take on an empty stomach with plain water and wait 30–60 minutes before food, calcium or other supplements.
Page updated: 2026-10-08 · By Prof. E. Shalaan, Applied Sciences and AI (ASAI)