Pediatric reference value distributions for vitamins A and E in the CALIPER cohort and establishment of age-stratified reference intervals.

Objectives: Vitamin A (retinol) and vitamin E (α-tocopherol) are fat soluble micronutrients most commonly measured in the pediatric population to monitor deficiencies due to malabsorption secondary to gastrointestinal (GI) disorders. One of the major challenges of vitamin A and E testing is the lack of reliable pediatric reference intervals which limits accurate interpretation of results. Here we report new pediatric reference intervals (RI) for both vitamins as part of the Canadian Laboratory Initiative for Pediatric Reference Intervals (CALIPER).