Celiac disease leads to the inability to consume certain grains -- namely, wheat, barley and rye. When you have the condition and eat those grains, your body's immune system reacts by attacking the lining of your small intestines, eventually destroying it. Since your intestinal lining absorbs nutrients, many people with undiagnosed celiac disease experience nutritional deficiencies, including iron deficiency anemia. In fact, anemia -- with its characteristic low hemoglobin levels -- can hint that you have celiac disease, even in the absence of other symptoms.
Hemoglobin, a protein in your blood carries oxygen. In healthy people, hemoglobin levels range from 13.8 to 17.2 g/dL in men and 12.1 to 15.1 g/dL in women. When you have iron deficiency anemia, you cannot absorb enough iron from your food, and your hemoglobin levels fall. Iron malabsorption due to all causes, including celiac disease, occurs more frequently in women, with up to 9 percent of women suffering from the condition. Fewer than 1 percent of men have iron malabsorption and iron deficiency anemia.
Classic celiac disease symptoms feature mainly gastrointestinal complaints, including diarrhea, flatulence, heartburn and abdominal pain. Meanwhile, both celiac disease and low hemoglobin levels -- below 13 g/dL in men and 12 g/dL in women -- can cause fatigue, dizziness and headaches. However, many people with celiac disease don't have any obvious symptoms, making it difficult for doctors to detect the condition. In many cases, iron deficiency anemia detected on a routine blood test may be the only indication that a person has iron malabsorption caused by celiac disease.
A study reported in July 2011 in the medical journal "Revista Española de Enfermedades Digestivas" looked at 98 patients, mostly women, who had iron deficiency anemia that couldn't be reversed with iron supplementation. The researchers tested the patients for celiac disease, and found it in 13 percent of patients. Another 13 percent of patients had early signs of the disorder, even though they didn't meet the generally accepted medical criteria for diagnosis.
Other researchers have found links between celiac disease and iron malabsorption as well. For example, a physician with the UCLA Department of Medicine notes in a case report that a 69-year-old woman with few celiac disease symptoms presented with a hemoglobin level of 10.4 m/dL. After a full workup, doctors concluded she had celiac disease.
To treat celiac disease, you need to follow a gluten-free diet, which means avoiding all foods that contain gluten, the protein found in wheat, barley and rye grains. Gluten appears in bread and cereal, along with other grain products such as cookies. Food manufacturers also add it to many processed food items as a thickener and filler. Once you've been on the diet for several months and your intestines have had a chance to heal, your iron malabsorption likely will reverse and your hemoglobin levels should rise into the normal range.