Vitamin D status in children, adolescents, and young adults with Crohn disease

Background: Crohn disease (CD) and vitamin D deficiency are associated with decreased bone mineralization. Objective: We examined the prevalence of and risk factors for hypovitaminosis D in children, adolescents, and young adults with CD. Design: Growth, clinical characteristics, vitamin D intake (micrograms/d), and bone mineral density (g/cm2) were measured in a cross-sectional study of 112 subjects (44 females) who had CD and were 5-22 y of age. Hypovitaminosis D was defined as a serum concentration of 25-hydroxyvitamin D [25(OH)D] < 38 nmol/L. Results: The mean (+/- SD) serum concentration of 25(OH)D was 59.7 +/- 26.9 nmol/L, and 16% (95% CI: 9.3%, 23%) of the subjects had hypovitaminosis D. Hypovitaminosis D was most prevalent during the winter (31%; P = 0.02), among the African Americans (56%; P = 0.01), in the subjects with CD confined to the upper gastrointestinal tract (44%; P = 0.05), and in the subjects with a greater lifetime exposure to glucocorticoid therapy (23.7 ± 13.5 compared with 17.5 +/- 12.2 mg/d; P = 0.05). There was no association between hypovitaminosis D and either bone mineral density (P = 0.10) or average dietary intake of vitamin D (4.6 +/- 3.6 micrograms/d; P = 0.87). Conclusions: In this sample of pediatric patients with CD, hypovitaminosis D was common and was associated with the winter season, African American ethnicity, CD confined to the upper gastrointestinal tract, and magnitude of lifetime exposure to glucocorticoid therapy. The occurrence of these factors should prompt assessment of 25(OH)D status and clinical care optimized by supplementing subjects who have low serum concentrations. The physiologic relevance of ethnicity on 25(OH)D status in children with CD remains to be determined.