🧬 Family & Essentiality

🌿 Plain-Language Summary

Iron is vital for oxygen transport in the blood (haemoglobin) and muscles (myoglobin). It also supports energy metabolism, cognitive development, and immune defences. Haem iron (from animal foods) is absorbed more efficiently than non-haem iron (from plants and fortified foods).

⚗️ Molecular & Chemical IDs

• Element: Fe (Iron)
• Atomic number: 26
• Common supplement forms: ferrous sulphate, ferrous fumarate, ferrous gluconate; heme iron polypeptide

⚡ Functions

• Oxygen transport via haemoglobin and myoglobin
• Cofactor in oxidative enzymes and electron transport chain
• Supports cognitive development, memory, and learning
• Contributes to normal immune cell activity

🍽️ Absorption & Bioavailability

Absorption averages ~18% in mixed Western diets and ~10% in vegetarian diets.

🥗 Food Sources

• Haem: red meat, poultry, seafood
• Non-haem: legumes, whole grains, fortified cereals, leafy greens (absorption improved with vitamin C)

🇦🇺 Australian NRVs (NHMRC)

• RDI (Men): 8 mg/day
• RDI (Women 19–50 yrs): 18 mg/day
• RDI (Women 51+): 8 mg/day
• Pregnancy: 27 mg/day
• Lactation: 9 mg/day
• UL (Adults): 45 mg/day

🚨 Deficiency & Excess

Deficiency

Leads to iron-deficiency anaemia with symptoms such as fatigue, reduced work capacity, impaired cognition, brittle nails, and pallor. At-risk groups include menstruating women, pregnancy, infants/toddlers, vegetarians, endurance athletes, and people with GI disease.

Excess / Overload

High-dose supplements may cause GI upset. Genetic condition hereditary haemochromatosis increases risk of overload and requires medical supervision. Avoid unnecessary supplementation unless deficiency is diagnosed.

🧪 Testing & Monitoring

• Ferritin: reflects iron stores (low = deficiency)
• Transferrin saturation: shows circulating iron supply
• Full blood count (FBC): detects anaemia
• Consider CRP to rule out inflammation when interpreting ferritin
• Genetic testing for haemochromatosis in at-risk families

🔄 Interactions

• Iron supplements can reduce absorption of zinc, calcium, and some antibiotics — separate doses by at least 2 hours
• Vitamin C enhances non-haem iron absorption
• Tea, coffee, and phytate-rich foods reduce absorption if consumed with meals

📊 Evidence Snapshot

• 🔬✅ Well-established: Iron supplementation treats deficiency anaemia, improving energy, cognition, and work performance
• 🧪⚖️ Mixed: Routine supplementation in non-deficient individuals shows limited benefit and potential risks