As noted in previous blog posts (see links below), vitamin D has received a great deal of attention with a number of chronic diseases. In this latest study from CHOP, the incidence and mechanisms of vitamin D deficiency in pediatric Crohn’s disease are explored (Inflamm Bowel Dis 2013; 19: 45-33).
At diagnosis (2002-2005), Crohn’s disease (CD) participants (n=78) had their serum vitamin D assays and parathyroid hormone (PTH) levels checked. Then, these values were sequentially followed at 6 months, 12 months, and a median of 43 months later (n=52). The average age of the CD patients was 12.7 years.
- 42% of CD participants were 25-OH D deficient (<20 ng/mL) with an odds ratio of 2.1 compared with controls.
- Among patients with 25-OH D <30 ng/mL, CD patients had a lower PTH than controls.
- At final visit, 3% remained 25-OH D deficient and PTH levels corrected.
- Risk factors, besides CD, for vitamin D deficiency: black race (OR 10.4), visit in winter (OR 2.4), age 12 to <15 (OR 2.7), age >15 (OR 3.2). Greater disease activity was associated with lower vitamin D levels at baseline.
Implications of this study:
- Vitamin D deficiency normally causes secondary hyperparathyroidism. With newly-diagnosed CD, there was a relative hypoparathyroidism that resolved with therapy. “It is conceivable that proinflammatory cytokines associated with CD …prevent an appropriate PTH response.”
- The authors state that ‘vitamin D deficiency likely contributes to the pathogenesis of CD through effects on T and B lymphocyte, macrophage, and dendritic cell regulation.” Correcting vitamin D deficiency may improve CD treatment response in addition to potential improvements in bone health.