Celiac.com 09/21/2026 – Iron deficiency anemia is often blamed on blood loss, poor diet, or other common causes, but a new study highlights another possibility that can be easy to overlook: celiac disease. Researchers in Morocco examined patients being treated for iron deficiency anemia and found that some had underlying celiac disease, including people whose condition might not have been recognized if doctors had focused only on typical digestive symptoms.
The findings reinforce an increasingly important message about celiac disease. It does not always announce itself with diarrhea, abdominal pain, or obvious digestive problems. In some people, anemia and nutritional deficiencies may be among the strongest clues that the small intestine is being damaged by gluten.
Researchers Looked for Celiac Disease in Patients With Iron Deficiency Anemia
The study reviewed medical records from 635 patients who were treated for iron deficiency anemia at a hospital in Casablanca, Morocco, between January 2020 and September 2025.
Not every patient was tested for celiac disease. Ninety-seven underwent blood testing for antibodies associated with celiac disease, generally because their doctors suspected an underlying intestinal problem. Eighteen had positive antibody tests.
Those 18 patients underwent a biopsy of the small intestine. Seventeen had intestinal changes consistent with celiac disease. One additional patient had strongly positive celiac disease blood testing but a normal biopsy and was classified as having potential celiac disease.
Together, these 18 patients represented about 2.8 percent of the entire group of 635 patients with iron deficiency anemia.
However, the researchers stressed that this percentage should not be considered the true rate of celiac disease among everyone with iron deficiency anemia. Because only selected patients were tested, the study cannot determine how many additional cases might have been discovered if all 635 patients had undergone celiac disease screening.
All of the Identified Patients Were Female
One striking characteristic of the group was that all 18 patients were female. Their average age was about 30 years, although ages ranged from 11 to 47 years.
Most did not have a known family history of celiac disease. Only about 22 percent reported celiac disease in their family, meaning that the majority would not necessarily have been considered high-risk based on family history alone.
More than half had a history of gastritis, while smaller numbers had thyroid problems, obesity, type 2 diabetes, or high blood pressure.
Fatigue Was Universal, but Digestive Symptoms Varied
Every patient experienced significant weakness or fatigue, which is a common consequence of anemia. About 61 percent also had visible paleness, while some reported muscle cramps or hair loss.
Digestive symptoms were common but were far from identical among patients. About 83 percent reported intestinal discomfort, approximately two-thirds experienced weight loss, and slightly more than half had abdominal pain.
Chronic diarrhea occurred in about 44 percent, while fewer than 30 percent experienced fatty stools associated with poor nutrient absorption.
This is important because more than half of the patients did not have chronic diarrhea, one of the symptoms traditionally associated with celiac disease. A person could therefore have substantial intestinal damage and iron deficiency without fitting the classic picture many people associate with the condition.
Symptoms Extended Well Beyond the Digestive System
The study also documented several symptoms outside the digestive tract.
Nearly 39 percent of patients reported joint pain, while about 28 percent experienced bone pain. Some developed recurring mouth sores.
Reproductive problems were also present. Approximately 22 percent had experienced loss of menstrual periods, and about 17 percent reported a history of miscarriage.
These findings illustrate the wide range of ways celiac disease can affect the body. Damage to the small intestine can interfere with absorption of nutrients that are important not only for blood production but also for bones, muscles, reproductive health, and other body systems.
Iron Stores Were Often Severely Depleted
The anemia in these patients was generally substantial rather than borderline.
The average hemoglobin level was about 9.9 grams per deciliter. More than 72 percent of the patients had moderate anemia, while nearly 17 percent had severe anemia.
Iron storage levels were particularly low. Nearly all of the patients had ferritin below 15 nanograms per milliliter, and one-third had levels below 5 nanograms per milliliter, indicating profound depletion of stored iron.
Interestingly, the size of the red blood cells was not abnormal in everyone. About 56 percent had the small red blood cells typically associated with iron deficiency, while approximately 44 percent had red blood cells within the normal size range.
This means that normal red blood cell size should not necessarily rule out serious iron deficiency or celiac disease.
Other Nutritional Deficiencies Were Common
The researchers also examined folate and vitamin D levels in nine of the patients.
Among those tested, about 44 percent were deficient in folate, while approximately 67 percent were deficient in vitamin D.
Because only half of the patients were tested for these nutrients, the study cannot establish how common these deficiencies were across the entire group. Still, the findings are consistent with a broader pattern of nutrient malabsorption in people whose small intestine has been damaged by celiac disease.
Most Patients Had Significant Intestinal Damage
The intestinal biopsy results provided further evidence that celiac disease may remain undetected until substantial damage has developed.
Seventeen of the 18 patients showed biopsy findings compatible with celiac disease. Two-thirds had advanced intestinal damage involving flattening or destruction of the tiny finger-like structures that normally absorb nutrients from food.
Only one patient had a normal biopsy despite strongly positive celiac disease blood testing. This person was classified as having potential celiac disease and was included because the overall clinical and laboratory picture remained strongly suggestive of the condition.
Among patients who underwent examination of the stomach, gastritis was also common, and about half tested positive for Helicobacter pylori infection.
Treatment Included Both a Gluten-Free Diet and Iron Replacement
All 18 patients began a gluten-free diet after being identified as part of the celiac disease spectrum.
Every patient also received treatment to replace depleted iron stores. Two-thirds were treated with oral iron, while one-third required iron given directly into a vein.
This combination addresses both sides of the problem. Iron replacement can help restore iron stores and correct anemia, while removing gluten addresses the underlying intestinal injury caused by celiac disease.
The Study Has Important Limitations
This research was conducted at a single hospital and involved only 18 patients with confirmed or potential celiac disease. It was also based on existing medical records rather than a prospectively designed screening program.
The biggest limitation is that only 97 of the 635 patients with iron deficiency anemia received celiac disease blood testing. Doctors selected patients for testing based largely on clinical suspicion.
As a result, the reported 2.8 percent figure cannot be interpreted as the actual prevalence of celiac disease among people with iron deficiency anemia. Testing every patient could have produced a different result.
The researchers also lacked complete long-term information showing how consistently patients followed the gluten-free diet or how their anemia and celiac disease blood tests changed after treatment.
Why This Study Matters for People With Celiac Disease
The most meaningful message from this study is that iron deficiency anemia can be much more than a secondary laboratory finding. In some people, it may be one of the strongest clues that undiagnosed celiac disease is damaging the intestine.
This is particularly important because celiac disease does not always produce dramatic gastrointestinal symptoms. Someone may primarily experience fatigue, low iron stores, joint or bone pain, reproductive problems, or other nutritional deficiencies while the underlying intestinal disease goes unrecognized.
For people who already have celiac disease, the findings also emphasize the importance of monitoring iron and other nutrient levels, particularly when fatigue or anemia persists. Following a gluten-free diet is essential, but nutritional recovery may require identifying and correcting deficiencies that developed before diagnosis.
For those who have unexplained, persistent, or recurring iron deficiency anemia, especially when iron treatment alone does not solve the problem, this study supports considering celiac disease as a possible underlying cause. Recognizing that connection earlier could lead to faster diagnosis, appropriate treatment, and prevention of years of ongoing intestinal damage and nutritional depletion.
Read more at: cureus.com
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