Does concurrent use of acid blockers and iron supplements exacerbate iron deficiency anemia, and should the underlying cause of iron deficiency be investigated?

From the Guidelines

Taking an acid blocker with iron supplements can significantly reduce iron absorption, so it is recommended to take your iron supplement at least 2 hours before or 4 hours after your acid blocker. Stomach acid is essential for converting dietary iron into a form your body can absorb, so acid blockers like omeprazole, pantoprazole, or famotidine can interfere with this process 1. For better absorption, take iron on an empty stomach with vitamin C (like orange juice) and avoid taking it with calcium, dairy, coffee, tea, or antacids.

Regarding the cause of your iron deficiency, postpartum blood loss is likely contributing, but persistent iron deficiency should be investigated. Common causes include heavy menstrual periods, gastrointestinal bleeding (including from ulcers), celiac disease, or other absorption issues. According to the British Society of Gastroenterology guidelines, approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract 1.

Key Points to Consider

• Postpartum blood loss may be a contributing factor to your iron deficiency
• Persistent iron deficiency should be investigated to rule out underlying causes such as gastrointestinal bleeding or celiac disease
• The British Society of Gastroenterology guidelines recommend investigating the underlying cause of IDA, especially in adults without an obvious explanation 1
• IDA can be caused by a range of GI pathologies, including cancer, and swift and complete investigation is crucial 1

I recommend following up with your doctor to discuss further testing, which might include blood tests and possibly endoscopy or colonoscopy to rule out bleeding sources. While continuing your iron supplements, focus on iron-rich foods like lean red meat, beans, spinach, and fortified cereals to help rebuild your iron stores.

From the Research

Iron Absorption and Acid Blockers

• The patient is concerned about the potential interaction between her acid blocker and iron supplements, which may be affecting her iron absorption 2.
• A study published in JAMA found that certain antacids, such as sodium bicarbonate and calcium carbonate, can decrease iron absorption, while others like aluminum hydroxide and magnesium hydroxide do not have a significant effect 2.

Timing of Iron Supplement Intake

• Research suggests that taking iron supplements in the morning, away from meals and coffee, can maximize absorption 3.
• A study published in the American Journal of Hematology found that taking iron supplements with ascorbic acid (vitamin C) can increase absorption by 30% 3.
• Another study published in Haematologica found that taking iron supplements on alternate days can increase absorption compared to consecutive day dosing 4.

Investigating the Cause of Low Iron

• The patient's doctor initially mentioned the possibility of an ulcer, but it was not further investigated.
• It is essential to identify and address the underlying cause of iron deficiency anemia to prevent recurrence and ensure effective treatment.
• The patient may want to discuss further testing or evaluation with her doctor to determine the cause of her low iron levels.

Role of Vitamin C in Iron Supplementation

• Vitamin C can aid in increasing iron absorption and has antioxidant properties that can help prevent liver damage caused by iron overload 5, 6.
• However, a randomized clinical trial published in JAMA Network Open found that oral iron supplements alone were equivalent to oral iron supplements plus vitamin C in improving hemoglobin recovery and iron absorption in patients with iron deficiency anemia 6.