Normal fecal calprotectin levels in healthy children are higher than in adults and decrease with age.

Background/objectives: The paediatric reference range of fecal calprotectin (FC) has not been decisively established and previous studies show a wide within-age variability, suggesting that other factors like anthropometric data or type of feeding can influence FC. Our aims were to establish the normal levels of FC in healthy children grouped by age and analyze whether sex, gestational age, birth weight, type of delivery, type of feeding, or anthropometric data influence FC values.

Methods: This multicentre, cross-sectional, and observational study enrolled healthy donors under 18 years of age who attended their Primary Health Care Centre for their routine Healthy Child Program visits.