Celiac disease frequently causes low blood counts, most commonly manifesting as anemia, due to the body’s inability to absorb sufficient nutrients. Celiac disease is an autoimmune condition triggered by ingesting gluten, a protein found in wheat, barley, and rye. When a person with celiac disease consumes gluten, the immune system mistakenly attacks the lining of the small intestine. This sustained immune response damages the intestinal tract, directly interfering with nutrient uptake.
How Celiac Disease Impairs Nutrient Absorption
The small intestine is lined with millions of tiny, finger-like projections known as villi, which absorb nutrients from digested food into the bloodstream. In a person with untreated celiac disease, the immune reaction to gluten causes these villi to become inflamed and flattened, a process called villous atrophy. Villous atrophy severely reduces the absorptive surface area of the small intestine, often making the lining appear nearly flat. This structural damage prevents the body from effectively drawing essential vitamins and minerals from food.
This malabsorption means that even a well-balanced diet cannot provide the necessary building blocks for healthy bodily functions, directly causing nutritional deficiencies and low blood counts. The damage typically begins in the duodenum and jejunum, the upper parts of the small intestine, as these areas first encounter the highest concentration of digested gluten. The pattern of damage dictates which deficiencies are most likely to occur, since different nutrients are absorbed at specific locations. The severity of the villous atrophy correlates directly with the degree of malabsorption and the resulting nutritional deficits.
Specific Blood Count Deficiencies Linked to Celiac Disease
The most common hematological issue associated with celiac disease is anemia, a reduction in the number of red blood cells or a decrease in their oxygen-carrying capacity. This condition results primarily from the malabsorption of three specific nutrients: iron, vitamin B12, and folate. Iron deficiency anemia (IDA) is the most prevalent blood count abnormality, often being the first sign leading to a celiac disease diagnosis.
Iron is primarily absorbed in the duodenum, where celiac-related damage is most pronounced. Impaired iron absorption leads to a shortage of the mineral needed to produce hemoglobin. This deficiency results in microcytic anemia, characterized by red blood cells that are unusually small and pale. Many adults with celiac disease present with IDA resistant to standard oral iron supplements because the intestinal damage prevents absorption.
Celiac disease can also lead to deficiencies in folate (vitamin B9) and vitamin B12, which are necessary for the maturation of red blood cells. Folate is absorbed in the jejunum, and its malabsorption can occur alongside iron deficiency. Vitamin B12 absorption occurs much further down in the terminal ileum.
A B12 or folate deficiency causes megaloblastic anemia, where red blood cells are abnormally large and immature. Since B12 is absorbed lower down, a deficiency in this vitamin often suggests the celiac disease has progressed to cause extensive damage throughout the small intestine. Though less frequent, severe malnutrition can also rarely affect other blood components, potentially leading to low counts of white blood cells (leukopenia) or abnormal platelet counts (thrombocytosis or thrombocytopenia).
Identifying and Treating Celiac-Related Blood Issues
Identifying blood count issues related to celiac disease begins with routine blood work, specifically a complete blood count (CBC). This test confirms the presence of anemia and indicates the type by measuring red blood cell size, helping differentiate between microcytic and macrocytic anemia. If anemia is found, further testing pinpoints the exact nutritional deficiency, including blood tests to measure ferritin (stored iron), vitamin B12, and folate levels.
Anemia that does not resolve with typical treatments, or that is present without an obvious cause, should prompt testing for celiac disease, as the hematological problem is often the first noticeable manifestation. Once celiac disease is confirmed through antibody testing and an intestinal biopsy, treatment for the blood issue involves a two-pronged strategy.
For significant deficiencies, high-dose oral supplements may be prescribed for iron and folate, or injections may be necessary for vitamin B12 if damage prevents oral absorption. The long-term treatment is strict adherence to a gluten-free diet (GFD). The GFD stops the immune response, allowing the small intestine’s villi to heal over time. As the intestinal lining repairs itself, its ability to absorb nutrients is restored, resolving the underlying cause of the low blood count. While symptoms often improve quickly, it can take several months to a year for the lining to fully heal and for blood counts to stabilize completely.