Does consuming citrus fruits like oranges increase iron absorption when prescribing iron supplements, such as ferrous (iron) sulfate?

Iron Absorption Enhancement with Citrus Fruits

Yes, consuming citrus fruits like oranges can significantly enhance iron absorption when prescribing iron supplements, and this approach is recommended for patients with iron deficiency. 1

Mechanism and Evidence

Iron absorption can be significantly improved when taken with vitamin C (ascorbic acid), which is abundant in citrus fruits. This works through several mechanisms:

• Vitamin C acts as a powerful enhancer of non-heme iron absorption 1
• Citrus fruits contain both ascorbic acid and citric acid, which work synergistically to promote iron absorption 2, 3
• Research shows that orange juice can increase iron absorption from ferrous fumarate by approximately 50% (from 5.5% to 8.2%) 4

Clinical Recommendations

Optimal Administration

• Take iron supplements alongside citrus fruits/drinks to aid absorption 1
• For maximum benefit, consume the citrus fruit at the same time as the iron supplement
• The British Obesity and Metabolic Surgery Society specifically recommends taking iron supplements with citrus fruits/drinks to enhance absorption 1

Dosing Considerations

• Standard dosing for adults is 100-106 mg elemental iron once daily 5
• For improved tolerability and potentially better absorption, consider alternate-day dosing with 50-100 mg elemental iron 5
• Morning dosing is generally preferred 5

Important Precautions

1. For patients with hemochromatosis:

   • Avoid supplemental vitamin C, especially during the iron depletion phase 1
   • Limit vitamin C to no more than 500 mg daily if supplementation is necessary 1
   • Consume citrus fruits alone, not in combination with other foods 1

2. Timing considerations:

   • Iron and calcium supplements should be taken 1-2 hours apart to avoid interference with absorption 1
   • Avoid taking iron with tea, as it interferes with absorption 5
   • Avoid taking iron with proton pump inhibitors, which can decrease absorption 5

Monitoring Response

• Check hemoglobin response within 4 weeks of starting therapy 5
• Expect a rise of 2 g/dL after 3-4 weeks of proper supplementation 5
• If no response after 4 weeks despite using citrus fruits, consider:
  • Checking adherence
  • Investigating ongoing blood loss
  • Evaluating for malabsorption
  • Switching to parenteral iron 5

Conclusion

The evidence strongly supports using citrus fruits to enhance iron absorption. This approach is particularly beneficial for patients with iron deficiency anemia and can help improve treatment outcomes while potentially allowing for lower iron doses, which may reduce gastrointestinal side effects.