Abstract
Normalization of acid-base homeostasis in chronic kidney disease (CKD) holds promise for mitigating disease progression, but whether efforts should focus on patients with low serum bicarbonate or high dietary acid load is unknown. Vallet et al. report that low urinary ammonia excretion independently associates with increased progression in moderate CKD. Whether this finding implicates differences in endogenous acid production or the ability to excrete an acid load in the pathogenesis of progression requires further study.