What is the relationship between iron levels (Iron) and anemia?

From the Guidelines

Iron deficiency is a critical factor in the development of anemia, and maintaining adequate iron levels is essential for preventing and treating anemia. The relationship between iron levels and anemia is well-established, with iron deficiency being a common cause of anemia worldwide 1. Iron deficiency can lead to a range of health problems, from mild iron depletion to severe iron-deficiency anemia, which can affect the functioning of several organ systems.

Iron Deficiency and Anemia

In iron deficiency anemia, the body lacks sufficient iron to produce hemoglobin, leading to a decrease in red blood cell production and oxygen-carrying capacity in the blood.

• Iron supplementation is the primary treatment for iron deficiency anemia, with oral iron supplementation being the first-line treatment 1.
• Intravenous iron formulations may be recommended for patients with severe anemia, gastrointestinal intolerance to oral iron, or malabsorption conditions 1.
• Regular monitoring of complete blood count, iron studies, and ferritin is essential during treatment to ensure adequate iron levels and prevent recurrence of anemia.

Maintaining Adequate Iron Levels

To maintain adequate iron levels, ferritin levels should be above 30 ng/mL, and normal feronemia levels should be maintained between 50-170 μg/dL for men and 40-150 μg/dL for women.

• Iron supplementation works by providing the necessary building blocks for hemoglobin synthesis, allowing for increased red blood cell production and oxygen-carrying capacity in the blood 1.
• A recent study found that post-treatment serum ferritin levels of >400 μg/L can prevent recurrence of iron deficiency within the following 1–5 years 1.
• Alternate day oral iron supplementation may be a effective strategy to improve iron absorption and reduce the risk of anemia recurrence 1.

From the FDA Drug Label

In patients with iron deficiency, red cell uptake of radiolabeled iron ranged from 91% to 99% at 24 days after Injectafer dose In patients with renal anemia, red cell uptake of radiolabeled iron ranged from 61% to 84% at 24 days after Injectafer dose. The primary etiologies of IDA were heavy uterine bleeding (47%) and gastrointestinal disorders (17%) Increases from baseline in mean ferritin (264.2 ± 224.2 ng/mL in Cohort 1 and 218.2 ± 211. 4 ng/mL in Cohort 2), and transferrin saturation (13 ± 16% in Cohort 1 and 20 ± 15% in Cohort 2) were observed at Day 35 in Injectafer-treated patients Iron deficiency was defined as serum ferritin <100 ng/mL or 100 to 300 ng/mL with TSAT <20%. Following intravenous administration, Venofer is dissociated into iron and sucrose and the iron is transported as a complex with transferrin to target cells including erythroid precursor cells.

The relationship between iron levels and anemia is that low iron levels can cause anemia, specifically iron deficiency anemia (IDA).

• Iron is essential for the production of hemoglobin, a protein in red blood cells that carries oxygen to the body's tissues.
• Anemia occurs when the body does not have enough red blood cells or the red blood cells do not have enough hemoglobin.
• Iron deficiency can lead to a decrease in hemoglobin production, resulting in anemia.
• The studies show that increasing iron levels through intravenous administration of iron supplements, such as Injectafer or Venofer, can help improve hemoglobin levels and treat anemia 2, 3.
• Key indicators of iron deficiency anemia include low ferritin levels, low transferrin saturation (TSAT), and low hemoglobin levels.

From the Research

Relationship Between Iron Levels and Anemia

• Iron deficiency is a significant cause of anemia, accounting for 5% of cases in American women and 2% of cases in American men 4.
• The primary treatment for iron deficiency anemia is oral iron supplementation, which is effective in correcting the condition but may cause gastrointestinal side effects 5.
• Recent studies suggest that alternate-day oral iron supplementation may be more effective than daily supplementation in maximizing fractional iron absorption and reducing side effects 6, 7.
• Hemoglobin response at day 14 of oral iron supplementation can be a useful indicator of whether a patient will respond to treatment, with a ≥1.0-g/dL increase in hemoglobin predicting a satisfactory overall response 8.
• Intravenous iron supplementation may be necessary for patients who do not respond to oral iron or have severe iron deficiency anemia, and newer formulations have improved safety profiles 4, 5.

Iron Supplementation Strategies

• Oral iron supplementation is typically administered in doses of 60-120 mg elemental iron per day, with some studies suggesting that alternate-day dosing may be more effective 6, 7.
• The choice of iron formulation, such as ferrous sulfate or ferric maltol, may affect tolerability and efficacy 5.
• Ascorbic acid may enhance iron absorption when taken with oral iron supplements 6.
• Intravenous iron supplementation can rapidly achieve therapeutic targets without gastrointestinal complications, but may be reserved for patients who do not respond to oral iron or have severe iron deficiency anemia 4, 5.