We would like to thank Dr. Kokiwar et al.1 for their interest in our recent article on renal net acid excretion (NAE) in childhood and adolescence and circulating uromodulin in young adulthood.2 The authors have raised several important and thoughtful issues and acknowledged that our work usefully extended life course nutrition–kidney biomarker examinations into a nephrolithiasis-relevant research on an important tubular integrity marker. The first point they have addressed is related to an inconsistent description of the blood sample type used for uromodulin measurement.