Can celiac disease cause iron deficiency and low ferritin even without diarrhea?

Celiac disease is a primary cause of malabsorptive iron deficiency, as the disease specifically targets the proximal small intestine where the majority of dietary iron is absorbed. Modern clinical data highlights that iron deficiency is often the first, and sometimes only, clinical sign of the disease.

Clinical and effectiveness evidence

Extensive clinical research confirms that iron deficiency anemia (IDA) is one of the most common non-classical presentations of celiac disease.

• Prevalence in IDA: Approximately 3% to 5% of patients presenting with unexplained iron deficiency are ultimately diagnosed with celiac disease.
• Presentation Patterns: In contemporary cohorts, up to 50% of newly diagnosed celiac patients do not exhibit classic gastrointestinal symptoms like chronic diarrhea or steatorrhea.
• Ferritin Levels: Low serum ferritin is a highly sensitive marker for the depleted iron stores caused by the chronic malabsorption inherent in celiac disease.

Mechanistic explanations

The localized nature of iron absorption in the gut explains why iron deficiency can occur even when other digestive functions seem normal.

• Site-Specific Damage: Iron absorption is highly concentrated in the duodenum and proximal jejunum. Celiac-induced villous atrophy—the flattening of the intestinal lining—is often most severe in these proximal sections.
• Transporter Loss: The autoimmune response reduces the density of Divalent Metal Transporter 1 (DMT1) and ferroportin, the specialized molecular "pumps" required to move iron from the intestinal lumen into the bloodstream.
• Hepcidin Mediation: Systemic inflammation from active celiac disease can increase hepcidin levels, which further blocks iron export from intestinal cells, exacerbating the deficiency.

Clinical implications

Because the damage can be limited to the proximal gut, patients may maintain enough distal intestinal function to avoid diarrhea while still developing severe iron depletion.

• Screening Standards: International guidelines (e.g., ACG, BSG) now mandate celiac disease screening for any patient with unexplained iron deficiency, regardless of whether they report gastrointestinal distress.
• Resolution: Research shows that most patients (70–90%) see a resolution of iron deficiency within 6 to 12 months of adhering to a strict gluten-free diet, as the proximal intestinal mucosa heals and restores its absorptive capacity.

Bottom line

Celiac disease is a frequent cause of "silent" iron deficiency. Because iron absorption is uniquely localized to the area of the gut most damaged by gluten, low ferritin and anemia are often the earliest or sole indicators of the disease, even in the absence of diarrhea.