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Iron

Mineral Unit: mg

Essential mineral needed for oxygen transport in blood (haemoglobin) and energy production. Deficiency causes anaemia.

Recommended Daily Allowance (RDA)

8.0
Adult Male
mg/day
18.0
Adult Female
mg/day
Daily Requirements by Life Stage 16 groups
Life StageRDA / AI (mg/day)Upper Limit (mg/day)
Children 1-3 years7.040.0
Children 4-8 years10.040.0
Males 9-13 years8.0
Females 9-13 years8.0
Males 14-18 years11.0
Females 14-18 years15.0
Males 19-30 years8.045.0
Females 19-30 years18.045.0
Males 31-50 years8.0
Females 31-50 years18.0
Males 51-70 years8.0
Females 51-70 years8.0
Males 70+ years8.0
Females 70+ years8.0
Pregnancy27.045.0
Lactation9.045.0

Top Foods Highest in Iron

Amount per 100g serving. Values in mg per 100g.

Foods Highest in Iron (Table)

#FoodPer 100gGroup
1Spices, thyme, dried124 mgSpices and Herbs
2Spices, basil, dried89.8 mgSpices and Herbs
3Spearmint, dried87.5 mgSpices and Herbs
4Spices, marjoram, dried82.7 mgSpices and Herbs
5Whale, beluga, meat, dried (Alaska Native)72.3 mgAmerican Indian/Alaska Native Foods
6Cereals ready-to-eat, RALSTON Enriched Wheat Bran flakes67.7 mgBreakfast Cereals
7Babyfood, cereal, oatmeal, with honey, dry67.2 mgBaby Foods
8Seaweed, Canadian Cultivated EMI-TSUNOMATA, dry66.4 mgVegetables and Vegetable Products
9Spices, cumin seed66.4 mgSpices and Herbs
10Babyfood, cereal, oatmeal, dry fortified64.1 mgBaby Foods
11Babyfood, cereal, Oatmeal, dry, GERBER, SINGLE GRAIN, fortif64.0 mgBaby Foods
12Spices, turmeric, ground55.0 mgSpices and Herbs
13Parsley, freeze-dried53.9 mgVegetables and Vegetable Products
14Babyfood, cereal, rice, dry fortified53.0 mgBaby Foods
15Seal, bearded (Oogruk), meat, dried (Alaska Native)49.6 mgAmerican Indian/Alaska Native Foods
16Cereals, QUAKER, Quick Oats with Iron, Dry49.5 mgBreakfast Cereals
17Spices, dill weed, dried48.8 mgSpices and Herbs
18Babyfood, cereal, barley, dry fortified48.2 mgBaby Foods
19Babyfood, cereal, brown rice, dry, instant47.6 mgBaby Foods
20Babyfood, rice cereal, dry, EARTHS BEST ORGANIC WHOLE GRAIN,47.5 mgBaby Foods

Health Effects of Iron

Function

Iron is essential for oxygen transport (hemoglobin), oxygen storage in muscles (myoglobin), energy production, and DNA synthesis. It exists in two dietary forms: heme (animal) and non-heme (plant).

Deficiency Signs

Iron deficiency is the world's most common nutritional deficiency, causing anemia, fatigue, impaired cognitive function, weakened immunity, and poor pregnancy outcomes. Affects ~2 billion people globally.

Excess / Toxicity

Iron overload (hemochromatosis) damages the liver, heart, and pancreas. Excess iron generates free radicals via the Fenton reaction. UL is 45mg/day for adults.

Absorption & Interactions

How It’s Absorbed

Heme iron (meat, fish) is absorbed directly by HCP1 transporter at 15-35% efficiency. Non-heme iron (plants, fortified foods) is absorbed via DMT1 at 2-20%, highly influenced by enhancers and inhibitors.

Key Interactions
Vitamin C Enhancer
Vitamin C converts Fe3+ to Fe2+ (the absorbable form), increasing non-heme iron absorption 2-6x. Just 25mg vitamin C with a meal doubles iron uptake
Calcium Inhibitor
300mg+ calcium with a meal reduces iron absorption by ~40-50%. Separate iron-rich meals from dairy
Dietary Fiber Inhibitor
Phytate in whole grains and legumes strongly inhibits non-heme iron absorption. Soaking, sprouting, and fermentation reduce phytate
Zinc Inhibitor
Iron and zinc compete for absorption when taken as supplements (not from food sources)
Copper Enhancer
Copper is needed to mobilize iron from stores; copper deficiency causes iron-refractory anemia

Estimated Iron Adequacy by Country

Estimated from national food supply composition (FAO food balance sheets). Shows food supply availability relative to Estimated Average Requirement (EAR), not actual intake. Does not account for fortification, supplements, or distribution inequality.

180 countries0 below 50% EAR180 above 100% EARAvg: 275% EAR
% of EAR from food supply:0-25%25-50%50-75%75-100%100-150%>150%

Frequently Asked Questions

How much Iron do I need per day?

Adult males need 8.0 mg/day and adult females need 18.0 mg/day.

Which food has the most Iron?

The food highest in Iron is Spices, thyme, dried with 124 mg per 100g.

What does Iron do in the body?

Essential mineral needed for oxygen transport in blood (haemoglobin) and energy production. Deficiency causes anaemia.