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Iron 2mg

Also known as: Iron (Fe), elemental iron, ferrous sulfate (FeSO₄), ferrous fumarate, ferrous gluconate, ferrous iron, ferric iron, Iron

Overview

Iron is an essential trace element vital for numerous physiological functions, including oxygen transport, cellular metabolism, and DNA synthesis. It is a key component of hemoglobin in red blood cells, which carries oxygen from the lungs to the rest of the body, and myoglobin, which stores oxygen in muscles. Iron also plays a crucial role in mitochondrial electron transport and various enzymatic reactions. Natural sources of iron include red meat, poultry, fish, legumes, and fortified cereals. Iron supplements are commonly available in various forms, such as ferrous sulfate, ferrous fumarate, and ferrous gluconate, with ferrous forms generally exhibiting higher bioavailability. Supplementation is primarily used to prevent and treat iron deficiency and iron deficiency anemia, particularly in vulnerable populations like children and women of reproductive age. Research indicates that iron supplementation can improve hemoglobin levels and cognitive function, especially in individuals with pre-existing deficiencies.

Benefits

Iron supplementation is primarily beneficial for improving hemoglobin levels and treating iron deficiency anemia, with typical increases of 1–2 g/dL within 3–4 weeks at adequate doses. In school-age children, iron supplementation has been shown to improve intelligence, attention, concentration, and memory, with effect sizes varying but generally positive and statistically significant. Studies suggest that cognitive improvements are most pronounced in children with baseline iron deficiency. Iron may also reduce fatigue and improve physical performance in iron-deficient individuals, although evidence for cognitive benefits in non-anemic adults is limited. The most robust evidence supports benefits for children and women of reproductive age, while benefits in non-deficient adults are less clear. Overall, iron supplementation is effective for addressing iron deficiency and related symptoms, particularly in vulnerable populations.

How it works

Iron functions primarily by being incorporated into hemoglobin and myoglobin, facilitating oxygen transport and storage. It is essential for mitochondrial electron transport, which is critical for energy production, and also plays a role in DNA synthesis. Iron interacts with various body systems, primarily affecting hematopoiesis (red blood cell production), oxygen delivery, and cognitive function through neurotransmitter synthesis and myelination. The absorption of iron occurs mainly in the duodenum and upper jejunum, with ferrous salts (sulfate, fumarate, gluconate) being the most bioavailable forms. Absorption is enhanced by vitamin C and inhibited by substances like calcium, phytates, and polyphenols, which can bind to iron and reduce its absorption.

Side effects

Iron supplementation is generally safe at recommended doses, but higher doses or prolonged use can increase the risk of adverse effects. Common side effects, occurring in more than 5% of users, include gastrointestinal discomfort such as nausea, constipation, diarrhea, and abdominal pain. Uncommon side effects, affecting 1–5% of users, may include vomiting and loss of appetite. Rare side effects, seen in less than 1% of users, can include severe allergic reactions and iron overload, especially with chronic excessive intake. Iron supplements can interact with certain medications, reducing the absorption of antibiotics like tetracyclines and quinolones. Absorption can also be inhibited by antacids and calcium supplements. Iron supplementation is contraindicated in individuals with hemochromatosis, chronic iron overload, or certain anemias not due to iron deficiency. Caution is advised in children and pregnant women, and monitoring for iron overload is recommended in at-risk populations.

Dosage

For children, a minimum effective dose of 2 mg elemental iron daily may be used for prevention, but higher doses (3–6 mg/kg/day) are typically required for therapeutic effect. Adults usually require 60–120 mg elemental iron daily for treating deficiency. The upper limit for adults is 45 mg/day from supplements unless under medical supervision. Iron supplements are best taken on an empty stomach to enhance absorption, but they can be taken with food to reduce gastrointestinal side effects. Ferrous sulfate, fumarate, or gluconate are preferred forms, while slow-release formulations may be less effective. Vitamin C enhances iron absorption, while calcium, phytates, and polyphenols inhibit it. Adequate folate and vitamin B12 are required cofactors for hematopoiesis.

FAQs

How should I take iron supplements for best absorption?

Take iron supplements separately from calcium-rich foods or supplements to maximize absorption. Taking them with vitamin C-rich foods or beverages can also enhance absorption. Avoid taking them with dairy or antacids.

Is iron supplementation safe for everyone?

Iron is not beneficial for everyone; supplementation is only warranted in deficiency or at-risk populations. Iron overdose is a leading cause of pediatric poisoning, so keep supplements out of reach of children.

How long does it take to see results from iron supplementation?

Hemoglobin improvement can typically be seen within weeks of starting supplementation. Cognitive benefits may take several months to manifest, particularly in children, so consistent adherence is important.

What are the common side effects of iron supplements?

The most common side effects include gastrointestinal issues like nausea, constipation, diarrhea, and abdominal pain. Taking iron with food can help reduce these side effects, but it may also slightly reduce absorption.

Can iron supplements interact with other medications?

Yes, iron supplements can interact with certain antibiotics (e.g., tetracyclines, quinolones), reducing their absorption. Antacids and calcium supplements can also inhibit iron absorption, so separate the timing of these medications.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/37368919/ – This study likely investigates the effects of iron supplementation on various health outcomes. Further information would be needed to provide a more detailed summary, but PubMed is a reliable source for biomedical literature.
https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0287703 – This systematic review and meta-analysis examined the effects of iron supplementation on cognitive function in school-age children. The study found that iron supplementation significantly improved intelligence, attention, concentration, and memory, although effect sizes were modest. The review included multiple RCTs and was considered high quality, despite some heterogeneity in study designs and outcome measures.
https://www.mdpi.com/2072-6643/14/24/5332 – This systematic review and meta-analysis assessed the impact of iron supplementation on cognitive function in both children and adults. The study revealed that iron supplementation improved cognitive function, particularly in children with baseline deficiency, while benefits in non-deficient adults were less clear. The review was considered moderate to high quality, with robust methodology but some heterogeneity in populations and outcome measures.
https://haematologica.org/article/view/haematol.2024.284967 – This article likely provides insights into hematological aspects related to iron. Further information would be needed to provide a more detailed summary, but Haematologica is a reputable journal in the field of hematology.
https://apps.who.int/iris/bitstream/handle/10665/204712/9789241549523_eng.pdf – This WHO systematic review and meta-analysis focused on the effects of daily iron supplementation in infants and children aged 4–23 months. The study found that daily iron supplementation reduced anemia and iron deficiency in young children, with moderate to high evidence quality for anemia outcomes. The review followed Cochrane standards, ensuring high methodological rigor.