| Summary: | BACKGROUND: Vitamin D is important for children with Crohn’s disease for the promotion of optimal bone health and because suboptimal vitamin D has been associated with increased disease activity through epidemiological and animal studies. Health Canada’s vitamin D Recommended Dietary Allowance for healthy children is 600 IU/d to promote serum 25-hydroxyvitamin D (25OHD) concentrations >50 nmol/L. There is little experimental evidence informing the dose of vitamin D required for children with Crohn’s disease.
OBJECTIVE: We aimed to determine whether a vitamin D₃ supplement of 2000 IU/day would achieve a higher prevalence of serum 25OHD concentrations >50 or 75 nmol/L compared to 400 IU/day, in children with quiescent Crohn’s disease. Exploratory objectives included assessing any difference between groups in the bone formation biomarker, bone specific alkaline phosphatase (BSAP), concentrations and disease activity, as measured by the Pediatric Crohn’s Disease Activity Index (PCDAI).
METHODS: Eighty-three children with quiescent Crohn’s disease (PCDAI <10) were recruited from British Columbia Children’s Hospital and McMaster Children’s Hospital and randomized to receive 400 or 2000 IU/d vitamin D₃ for 6 months. Clinical and biochemical data were collected at baseline, 3 months and 6 months.
RESULTS: Using an intention to treat analysis, at 6 months subjects receiving 2000 IU (vs. 400 IU) were more likely to achieve serum 25OHD concentrations >75 nmol/L (79% vs. 35%, P<0.001), but proportions >50 nmol/L did not differ (88% vs. 87%, p = 0.934). After adjustment for baseline 25OHD, mean serum 25OHD was higher in the 2000 IU group than the 400 IU group by 24 (95% CI: 15 – 33) nmol/L. Regimens were found to be equally safe based on the assessment of serum calcium and phosphate concentrations and urinary calcium to creatinine ratio, and no effect of vitamin D supplementation was observed on secondary objective outcome measures of serum BSAP concentration, or the PCDAI score.
CONCLUSION: A vitamin D₃ supplement dose of 2000 IU/d is more effective than 400 IU/d in promoting serum 25OHD concentrations >75nmol/L in children with quiescent Crohn’s disease, however both regimens are effective and safe in promoting concentrations greater than the current cutoff for adequacy of 50 nmol/L. === Land and Food Systems, Faculty of === Graduate
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