Development of age-dependent micronutrient centile charts and their utility in children with chronic gastrointestinal conditions at risk of deficiencies: A proof-of-concept study

Interpretation of blood micronutrient levels requires age-appropriate reference intervals. This study developed age-dependent micronutrient centiles for healthy children (HC) and explored their utility in sick children. 244 blood samples were collected from normal HC who underwent tests for acute illness. Age-dependent, centile charts were fitted for zinc, copper, magnesium and selenium in plasma and erythrocytes (RBC), and for vitamins B1, B2 and B6 in RBC. For 34 children with Crohn's disease (CrD) and 55 with coeliac disease (CoeD), Z-scores for the levels of these micronutrients were computed, using the new charts. Associations were explored between plasma and RBC micronutrient Z-scores, and in CrD with CRP and serum albumin. In HC, plasma zinc and selenium increased and plasma copper, magnesium and RBC vitamins B1, B2 and B6 decreased with age. In HC and in CrD, plasma and RBC Z-scores for copper, selenium and magnesium (all p