Nutrients

Iron: food, absorption and safe supplementation

Iron carries oxygen in blood and muscle and supports energy production, brain development, immunity and normal cell function. Low iron can occur before anaemia, so symptoms and blood results need clinical interpretation.

Reviewed August 2026

Haem and non-haem iron

Haem iron is found in meat, poultry, fish and seafood and is more readily absorbed. Non-haem iron is found in legumes, tofu, eggs, nuts, seeds, wholegrains, green vegetables and iron-fortified foods. Its absorption varies with meal composition and the body’s iron status.

Animal sources include lean beef or lamb, kangaroo, sardines, tuna, salmon, chicken and eggs.
Plant and fortified sources include iron-fortified cereal, lentils, beans, chickpeas, firm tofu, tempeh, pumpkin seeds, cashews, quinoa and wholegrain bread.

How much is needed?

Australian recommended intakes vary by age and life stage. Examples include 8 mg/day for adult men and women over 50, 18 mg/day for women aged 19–50, and 27 mg/day during pregnancy. Children and adolescents have age- and sex-specific requirements. Vegetarian diets may require more dietary iron because average absorption is lower; this does not mean everyone needs a supplement.

Improve absorption

Add vitamin C-rich capsicum, tomato, broccoli, kiwifruit, citrus or berries to a plant-iron meal.
If eaten, meat, fish or poultry can improve absorption of non-haem iron in the same meal.
Keep tea and coffee away from iron-rich meals—about an hour is a practical guide when iron status is low.
Do not take calcium supplements at the same time as an iron tablet. Calcium-rich foods remain important; timing matters more than avoidance.

Who is at greater risk?

Risk can be higher with heavy menstruation, pregnancy, rapid growth, endurance training, blood donation or other blood loss, low dietary intake, coeliac disease, inflammatory bowel disease, bariatric surgery, and vegetarian or vegan diets. In older adults, unexplained deficiency requires investigation rather than dietary treatment alone.

Symptoms need appropriate tests

Fatigue, reduced exercise tolerance, breathlessness, headaches, paleness, dizziness, restless legs, poor concentration, hair shedding or pica can occur with iron deficiency, but are not specific to it. Ferritin, haemoglobin, transferrin saturation and markers of inflammation may be needed to understand the pattern and find the cause.

Iron supplements

Oral products include ferrous salts, iron polymaltose and iron bisglycinate. Ferrous salts are commonly used and well absorbed but can cause nausea, constipation, abdominal discomfort and dark stools. Other forms may be better tolerated by some people, although benefits and evidence vary. The elemental iron amount—not simply the compound name—determines the dose.

Do not start high-dose iron without appropriate clinical advice. Iron can interact with medicines, and an ineffective or poorly tolerated product may require review rather than repeated self-adjustment. Keep every iron product locked away from children: overdose is a medical emergency.