Iron
Iron is an essential mineral vital for producing haemoglobin, the protein in red blood cells that transports oxygen throughout the body. It supports energy production, cognitive function, and immune health, while also aiding muscle metabolism and hormone synthesis. Research highlights its critical role in preventing iron deficiency anaemia, particularly in high-risk groups like pregnant women, young children, and those with limited dietary iron intake. Studies also suggest iron supplementation can improve fatigue, physical capacity, and cognitive development in deficient individuals.
Key Facts
- The UK recommended daily intake ranges from 8 mg for adult men to 18 mg for women aged 19–50, with pregnant women needing 27 mg.
- Over 30% of pregnant women globally experience iron deficiency, increasing risks of preterm birth and developmental delays in infants.
- Common deficiency symptoms include fatigue, pale skin, shortness of breath, and unusual cravings for non-food items like ice (pica).
- Iron supplements are available as tablets, intravenous infusions, or fortified foods, with doses tailored to deficiency severity.
- Vitamin C enhances iron absorption, while calcium supplements, tea, and coffee can inhibit it.
- Alternate-day iron supplementation shows comparable efficacy to daily dosing but with fewer gastrointestinal side effects.
What does the research say about iron and its function in the body?
Iron is crucial for oxygen transport, energy production, and neurological development. Studies demonstrate its effectiveness in reducing fatigue, improving cognitive performance in children, and preventing complications during pregnancy, such as low birth weight. Research also indicates that correcting deficiency can enhance physical endurance and immune response.
What are the primary food sources of iron?
Iron-rich foods include red meat, poultry, fish, lentils, spinach, and iron-fortified cereals. Cooking acidic foods like tomatoes in cast-iron pans can also boost iron content. Pairing these with vitamin C sources, such as oranges or broccoli, improves absorption.
How can I supplement iron?
When iron deficiency is suspected it can be used with typical doses of 100–200 mg elemental iron daily. Intravenous iron may be used for severe cases or poor tolerance to oral forms. Always consult a healthcare provider to determine the appropriate type and dosage.
What are the main symptoms of iron deficiency?
Early signs include fatigue, dizziness, and cold hands/feet. Severe deficiency can lead to brittle nails, hair loss, restless legs syndrome, and anaemia marked by pale skin, chest pain, or irregular heartbeat. Unusual cravings for non-nutritive substances (pica) are also red flags.
Are there any known side effects of supplementing iron?
Common side effects include constipation, nausea, and stomach cramps. These can often be mitigated by taking supplements with food or opting for alternate-day dosing. Intravenous iron may cause temporary flushing or metallic tastes but is generally well-tolerated.
How long does it take to see the benefits of iron supplementation?
Improvements in energy levels may occur within 2–3 weeks, while haemoglobin levels typically normalise in 1–2 months. Severe deficiency or anaemia might require 3–6 months of consistent supplementation.
What should consumers look for on the supplement label when supplementing iron?
Check for the type of iron (e.g., ferrous sulphate) and the amount of elemental iron per dose, as this determines bioavailability. Avoid formulas with calcium or antacids, which hinder absorption.
Can iron supplements interact with medications?
Yes—iron can reduce the effectiveness of antibiotics like tetracycline and levothyroxine. Take supplements 2 hours apart from these medications, calcium, or antacids to prevent interactions.
How much iron is too much?
Excess iron (over 45 mg/day for adults) may cause toxicity, leading to vomiting, liver damage, or organ failure. Never exceed prescribed doses unless directed by a healthcare provider.
Can I get enough iron through diet alone?
While possible with a balanced diet rich in meat, legumes, and fortified foods, at-risk groups (e.g., pregnant women, vegetarians) often require supplements to meet increased needs. Regular blood tests can help monitor levels.
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