We have been researching vitamins and nutrients recently, and this article summarizes what we found about potential nutrient gaps for people on gluten-free diets.
For individuals with celiac disease, a strict gluten-free diet is essential. Others may choose or need to avoid gluten for sensitivity or personal reasons. Regardless of the reason, it’s important to be aware that a gluten-free diet can increase the risk of deficiencies in several essential vitamins and minerals.
Many gluten-containing foods are naturally high in B vitamins and other nutrients, and commercially available gluten-free alternatives are not always enriched. Access to naturally gluten-free, nutrient-dense foods also varies by location and personal dietary choices, which can make it harder to meet recommended daily intakes.
Food fortification—adding nutrients back into processed foods—helps many people meet their needs. Because many gluten-free grain products aren’t fortified, people who rely heavily on them may struggle to get enough of certain vitamins compared with those eating conventional, fortified grains.
Why do nutrient deficiencies occur in people following a gluten-free lifestyle?
The most important factor is celiac disease. Celiac is an autoimmune condition that damages the lining of the small intestine when gluten is consumed. The immune response causes inflammation and flattens the villi, the tiny finger-like projections that absorb nutrients. When villi are damaged, nutrient absorption is impaired, which can lead to malabsorption and deficiencies.
Symptoms of malabsorption and resulting nutrient shortfalls may include anemia, fatigue, weight loss, muscle weakness, gastrointestinal symptoms and delayed growth in children. For people diagnosed with celiac disease, strict lifelong adherence to a gluten-free diet is necessary to allow intestinal healing and prevent ongoing damage.
Non-celiac gluten sensitivity produces uncomfortable symptoms—bloating, headaches, diarrhea and joint pain for example—but it does not cause the same villous atrophy as celiac disease. Symptoms typically improve when gluten is removed from the diet.
Common nutrient shortfalls linked to gluten-free diets
Vitamin D – Research indicates many people do not get enough vitamin D from food alone. People with celiac disease may also avoid dairy products, reducing intake of dietary vitamin D and calcium and increasing the risk of deficiency.
Folate (Vitamin B9) – Folate deficiency is common among people with untreated celiac disease. Folate must be converted in the intestine from various food forms by enzymes for absorption. When the intestinal lining is damaged, this conversion and absorption can be impaired, increasing the risk of low folate and related issues like anemia.
Vitamins B12 and B6 – B vitamins are absorbed in the small intestine, so damage to this area can reduce levels. Some long-term studies of celiac patients on gluten-free diets found normal B12 levels but a substantial portion with low B6. Levels often improve after intestinal healing, but monitoring remains important.
Many people with newly diagnosed celiac disease see their nutrient levels normalize as the intestine heals on a strict gluten-free diet. Still, evidence shows that gluten-free diets carry a higher risk of certain deficiencies compared with typical diets, even though nutrient gaps also occur in people who eat gluten.
If testing shows deficiencies, a healthcare provider can recommend appropriate supplements or dietary adjustments. Because individual tolerance and absorption vary, working with a clinician or registered dietitian helps ensure supplements and food choices are safe and effective.
As demand for gluten-free products grows, manufacturers are increasingly fortifying breads, pastas and other gluten-free staples. This trend should help reduce some nutrient gaps over time, but choosing naturally nutrient-rich, naturally gluten-free foods—such as leafy greens, legumes, nuts, seeds, dairy or fortified alternatives, and lean proteins—remains an important strategy.
Being informed, monitoring nutrient status, and consulting healthcare professionals when needed are practical steps for maintaining health on a gluten-free diet.