Standardizing vitamin D supplementation to minimize deficiency in children with intestinal failure

Background: Vitamin D deficiency is present in 40%–70% of children with intestinal failure (IF), yet there are no published guidelines for repleting and maintaining vitamin D levels in this population. The purpose of this study is to evaluate the efficacy of a standardized vitamin D algorithm in reducing the incidence of deficiency. Methods: A retrospective chart review was performed in children with IF who had at least one serum vitamin D (25-hydroxyvitamin D₃) measurement. Vitamin D levels were compared prealgorithm (2014–2016) and during active-algorithm use (2018–2020). Vitamin D levels were classified as severe deficiency (<12.5 nmol per L), mild deficiency (12.5–39 nmol/L), insufficiency (40–74 nmol/L), optimal (75–224 nmol/L), or toxicity (>225 nmol/L). Descriptive and comparative statistics were calculated using a linear mixed-effects model, with P < 0.05 considered significant. Results: Twenty-eight children with IF were enrolled, which included 157 vitamin D measurements (58 in the prealgorithm group and 98 in the active-algorithm group). Algorithm compliance was 4% in the prealgorithm group and 61% in the active-algorithm group. Active-algorithm patients had improved vitamin D levels in all categories compared with those of prealgorithm patients (mild deficiency: 8% vs 9%; insufficiency: 41% vs 72%; optimal: 50% vs 19%). Algorithm use was found to have a statistically significant effect on serum vitamin D levels (β = 21.58; 95% confidence interval, 14.11–29.05; P < 0.005). Conclusions: Children with IF are at high risk for vitamin D deficiency. Use of a standardized vitamin D supplementation algorithm was associated with increased serum vitamin D levels.