(18) Associations Between Vitamin D and Pediatric Celiac Disease

Background: Celiac disease (CD) is an autoimmune enteropathy elicited by the ingestion of gluten. Micronutrient insufficiencies are common in CD, and vitamin D has been linked to autoimmunity as a regulator of immune function and intestinal permeability. Thus, it is possible that vitamin D may play a role in CD development.

Objectives: This study aimed to investigate the prevalence of vitamin D insufficiency and deficiency in pediatric CD patients and determine if vitamin D status was associated with markers of disease severity.

Design/Methods: 151 pediatric patients at the University of Iowa Hospitals and Clinics were included in our study. Inclusion criteria included age 0-18 years, CD diagnosis by a pediatric gastroenterologist, and 25-hydroxy vitamin D recorded at diagnosis. A retrospective chart review was performed, and data including demographics, symptoms, past medical history, family history, growth parameters, clinical labs, the season labs were tested, histopathology, and vitamin supplementation were recorded both at diagnosis and at follow-up visits up to 18 months after diagnosis.

Results: 48% of patients were vitamin D insufficient ( < 30 ng/mL) and 17% were deficient ( < 20 ng/mL) at diagnosis. Those who were vitamin D insufficient or deficient at diagnosis were significantly less likely than those sufficient to have a family history of CD and more likely to have a higher body mass index Z-score. Vitamin D level was not significantly associated with age, serum tissue transglutaminase (tTg-IgA) antibody levels, or histopathology severity at diagnosis. Vitamin D level was also not significantly associated with tTg-IgA levels or length of time on a gluten-free diet at follow-up. There was also no significant difference in vitamin D levels between those with and without continued symptoms despite treatment at follow-up.

Conclusion: Our findings showed that vitamin D insufficiency is common in pediatric CD, with nearly half of the patients tested at diagnosis being insufficient. However, other recent studies suggest that vitamin D insufficiency and deficiency may be even more prevalent among the general U.S. pediatric population than what was found in our CD population. Additionally, we did not find that vitamin D was associated with serologic or histologic markers of disease severity or with continued symptomology despite treatment. These results indicate that there may be limited clinical utility for specifically testing for vitamin D in pediatric CD at diagnosis and follow-up. However, further research is necessary to continue to inform clinicians.