Micronutrient deficiencies are frequent in adult patients with and without celiac disease on a gluten-free diet, regardless of duration and adherence to the diet

The only treatment for celiac disease (CD) is a strict gluten-free diet (GFD). Nutritional deficiencies are common in CD; however, how this is influenced by the presence of symptoms, duration of CD, and compliance of GFD is less clear. The objective of this study was to compare nutritional deficiencies in patients with CD to those of nonceliac populations on a GFD. The secondary outcomes were to compare deficiencies in short- (<2 y) versus long-term (≥2 y) GFD, and in those with persistent symptoms versus asymptomatic. We included patients seen at the McMaster Celiac Clinic from June 2018 to August 2020. GFD adherence was assessed with the Celiac Dietary Adherence Test, and CD serology, vitamins, and trace minerals were measured in blood samples. We enrolled 221 patients, including 182 patients with CD and 39 controls. Overall, 103 of 182 patients with CD (56.6%) were following a GFD for >2 y and 119 patients (69.2%) were symptomatic. The most common micronutrient deficiencies were zinc (48.3%), ferritin (16.9%), and vitamin D (33.3%). There were no differences in micronutrient deficiencies between patients with CD and nonceliac controls, short- and long-term GFDs, or those strictly compliant with GFD and those who were fairly compliant ( P > 0.05). These data suggest that nutrient deficiencies may be related more to GFD nutritional inadequacy rather than malabsorption.