What is the most effective oral iron supplement and dosage for treating iron-deficiency anemia in adults?

From the Guidelines

For iron deficiency anemia in adults, the best oral iron supplement is ferrous sulphate, fumarate, or gluconate, with a recommended initial dose of one tablet per day. This recommendation is based on the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1. The guidelines suggest that if the initial dose is not tolerated, a reduced dose of one tablet every other day, alternative oral preparations, or parenteral iron should be considered.

When choosing an oral iron supplement, it is essential to consider the elemental iron content and potential side effects. Ferrous sulphate, fumarate, and gluconate are all effective options, with ferrous sulphate being a commonly prescribed formulation. The dose can be adjusted based on patient tolerance, with some patients preferring every-other-day dosing, which may be better tolerated with similar or equal rates of iron absorption as daily dosing 1.

Key considerations for oral iron supplementation include:

• Starting with a low dose and increasing as tolerated
• Taking the supplement on an empty stomach with vitamin C to enhance absorption
• Avoiding taking iron with calcium, dairy, coffee, tea, or antacids, which can reduce absorption
• Considering alternative formulations, such as ferrous gluconate or ferrous fumarate, if side effects occur
• Continuing treatment for 3-6 months after hemoglobin normalizes to replenish iron stores.

From the FDA Drug Label

CONTAINS: Each tablet contains 324 mg of ferrous sulfate, equivalent to 65 mg of elemental iron, providing 362% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older. DESCRIPTION Each tablet contains 324 mg of ferrous gluconate, equivalent to 38 mg of elemental iron, providing 211% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older. Directions for Use Do not crush or chew tablets. Adult Serving Size: 1 tablet three to four times daily. Children: Consult a physician. Suggested Use For Adults, take one (1) tablet daily or as directed by physician

The best oral iron supplement for iron deficient anemia in adults is ferrous sulfate due to its higher elemental iron content of 65 mg per tablet. The recommended amount is not explicitly stated in the label, but based on the available information, ferrous sulfate appears to be a suitable option. However, the exact dosage should be determined by a physician, as the label suggests. 2

From the Research

Oral Iron Supplements for Iron Deficient Anemia in Adults

• The most common oral iron supplement is ferrous sulfate, typically given at a dose of 325 mg/day or on alternate days 3.
• However, the effectiveness of ferrous sulfate can be reduced in patients taking proton pump inhibitors, such as omeprazole, due to decreased iron absorption 4.
• Alternative dosing regimens, such as taking ferrous sulfate every other day, may be effective and have fewer gastrointestinal side effects 5.
• Other oral iron supplements, such as lactoferrin, may have better effects on serum iron parameters and hemoglobin levels, with fewer side effects compared to ferrous sulfate 6.
• The choice of oral iron supplement and dosing regimen should be individualized based on patient factors, such as the presence of gastrointestinal side effects or concomitant medication use.

Comparison of Oral Iron Supplements

• Ferrous sulfate is a commonly used oral iron supplement, but it can have gastrointestinal side effects 3, 7.
• Lactoferrin may be a superior supplement to ferrous sulfate due to its better effects on serum iron parameters and hemoglobin levels, as well as its anti-inflammatory effects 6.
• The efficacy and safety of different oral iron supplements should be considered when selecting a treatment for iron deficient anemia in adults.

Dosing Regimens for Oral Iron Supplements

• The typical dosing regimen for ferrous sulfate is 325 mg/day or on alternate days 3.
• Alternative dosing regimens, such as taking ferrous sulfate every other day, may be effective and have fewer gastrointestinal side effects 5.
• The optimal dosing regimen for lactoferrin is not well established, but it may be effective at a dose of 100-200 mg/day 6.
• The dosing regimen for oral iron supplements should be individualized based on patient factors, such as the presence of gastrointestinal side effects or concomitant medication use.