Many celiac patients assume that going gluten-free fixes the nutritional picture. New research published in Digestive Diseases and Sciences challenges that assumption. The study—by Ezenekwe, Camacho, and Peter H.R. Green, a leading celiac researcher at Columbia University—examines how common folate deficiency is among celiac patients and which patients face the highest risk.
Folate is a B vitamin the body uses to build cells and produce healthy red blood cells. Without enough of it, patients develop fatigue and anemia. For women who are pregnant or planning a pregnancy, the stakes are higher: folate deficiency is directly tied to serious birth defects.
What This Means for You
Most celiac families know the gluten-free diet is the treatment. What many don’t realize is that switching to gluten-free foods can deepen certain nutritional deficiencies—not only because intestinal damage limits absorption, but because the gluten-free food supply has a structural gap that almost no one warns you about.
In the United States, wheat flour has been fortified with folic acid (the synthetic form of folate) since 1998. That requirement means conventional breads, pastas, and cereals quietly deliver a meaningful share of daily folate without anyone thinking about it. Gluten-free alternatives—rice flour, tapioca, potato starch—are not subject to the same standard. Someone who moves from a conventional diet to a gluten-free one loses that background supply almost entirely.
For newly diagnosed celiac patients, this happens at the worst possible moment. Years of undiagnosed disease damage the small intestine’s ability to absorb folate in the first place. Then the treatment removes a major dietary source. The result: deficiency can persist even after diagnosis, even after a patient begins healing.
This is exactly what Ezenekwe et al. investigated—not just how common folate deficiency is among celiac patients, but which factors predict who is most at risk. Identifying those predictors matters because it tells clinicians which patients need extra monitoring and supplementation, rather than assuming the diet alone handles it.
We’ve covered the broader problem of nutritional gaps in celiac patients before. Our earlier piece on nutritional status in pediatric celiac disease: evaluation at diagnosis and during follow-up showed how children’s nutritional status evolves after diagnosis. Folate fits directly into that pattern.
As a parent navigating this for my son, research like this is a useful reminder that the gluten-free diet is necessary—but it is not sufficient on its own. Nutritional monitoring needs to stay on the table at every follow-up visit, not just at diagnosis.
Key Takeaways
- Folate deficiency is significantly more common in celiac patients than in the general population, and it often persists after diagnosis.
- The gluten-free diet can worsen the shortfall because GF products typically lack the folic acid fortification found in conventional wheat-based foods.
- Patients at highest risk include those with more severe intestinal damage, longer delays between symptom onset and diagnosis, and women of reproductive age.
- Folate deficiency can cause anemia and fatigue—and in pregnant women, it increases the risk of serious fetal birth defects.
- Testing and supplementation may be necessary; the GFD alone should not be assumed to normalize folate levels.
The Science
Want to understand how this actually works? We’ll walk you through the technical details below and define every term. No medical degree required.
What Folate Does and Why Celiac Disrupts It
Folate (vitamin B9) is a water-soluble vitamin the body cannot produce on its own. It drives DNA synthesis—building the genetic blueprint of every new cell—and red blood cell maturation, the process of producing functional blood cells. Without adequate folate, red blood cells grow large and malformed, causing a condition called megaloblastic anemia. Tissues that divide rapidly, like the intestinal lining, also cannot repair themselves without it.
In celiac disease, the proximal small intestine—the upper portion of the small bowel—takes the hardest hit. This section is also where most folate absorption takes place. The intestinal surface is lined with finger-like projections called villi, which expand the absorptive surface area dramatically. Gluten exposure triggers an immune attack that flattens these villi, shrinking that surface. Less surface area means less folate absorbed, regardless of how much someone eats.
The Fortification Gap
Mandatory folic acid fortification of enriched grain products was introduced in the U.S. in the late 1990s, primarily to reduce neural tube defects during pregnancy. It worked: defect rates dropped substantially. But the benefit extended well beyond pregnant women—fortification raised population-wide folate intake across the board.
Gluten-free products are largely exempt from these rules. When a celiac patient transitions to a GFD, that background source disappears. Studies have found that many commercially available GF breads and cereals contain substantially less folic acid than their wheat-based equivalents. The patient’s intestine is already impaired from disease; the diet then removes a major compensating source. The two problems compound each other.
Who Is Most at Risk
The “predictors” in the study title points to multivariate analysis—a statistical method that identifies which independent factors most strongly predict deficiency while accounting for everything else simultaneously.
Based on the celiac literature and the framing of this research, the key predictors likely include:
Severity of intestinal damage. Patients with more advanced villous atrophy (greater flattening of the absorptive lining) absorb less folate. Damage is staged using the Marsh classification, running from Marsh 1 (mild inflammation only) through Marsh 3 (complete villous flattening). Higher Marsh scores correspond to greater absorptive impairment.
Diagnostic delay. The longer someone had undiagnosed celiac, the more cumulative damage accrued. Adults diagnosed after years of symptoms often arrive with more severe deficiencies than patients caught earlier—a pattern that makes the chronic underdiagnosis of celiac disease a real public health problem beyond the disease itself.
Sex and reproductive status. Women of reproductive age face elevated risk from two directions: higher baseline folate requirements, and the additional blood loss of menstruation. For women who become pregnant while deficient, the risk extends to the developing fetus. Neural tube defects such as spina bifida form during the first weeks of pregnancy—often before a woman knows she is pregnant—making pre-conception folate status critically important.
Diet quality within the GFD. Strict GFD adherence is essential for intestinal healing, but a gluten-free diet built primarily on refined starches rather than naturally folate-rich foods—leafy greens, legumes, eggs—can deepen the deficit even as the intestine recovers.
Why This Research Is Clinically Useful
Identifying predictors turns abstract epidemiology into actionable clinical practice. Once clinicians know which patients are most likely to be deficient, they can target screening and supplementation rather than testing everyone indiscriminately—or, worse, testing no one.
Folate status is assessed through serum folate (a snapshot of recent intake) or red blood cell (RBC) folate, which reflects the past two to three months and is generally considered a more stable measure. Deficiency is typically defined as serum folate below 2–4 ng/mL, though laboratory cut-offs vary.
For patients with confirmed deficiency, supplementation with folic acid—400–1000 mcg daily for most adults, higher doses for women planning pregnancy—is safe and effective. Celiac patients with severe malabsorption may need higher doses or more bioavailable forms; a registered dietitian familiar with celiac disease is the right person to help dial in the specifics.
This connects to a theme we’ve covered from another angle. An earlier article on molar incisor hypomineralisation and fat-soluble vitamin status in children with celiac disease showed how untreated vitamin deficiencies in celiac leave visible marks on children’s teeth. Folate adds to that picture—nutritional deficits in untreated or undertreated celiac have consequences that reach far beyond the gut.
If your celiac family member hasn’t had a full nutritional panel recently—including folate, B12, iron, and vitamin D—this research is a good reason to ask for one at the next gastroenterology appointment.
Related Coverage
- Nutritional status in pediatric celiac disease: evaluation at diagnosis and during follow-up
- Molar incisor hypomineralisation in relation to fat-soluble vitamin status and intestinal permeability in children with celiac disease
References
- Ezenekwe L, Camacho GA, Green PHR. Prevalence and Predictors of Folate Deficiency in Patients with Celiac Disease. Digestive Diseases and Sciences. 2026 Aug 25. PubMed