SummaryBackground and objectives Hyperphosphatemia, vitamin D deficiency, hyperparathyroidism, and high serum fibroblast growth factor 23 (FGF23) levels, when studied separately, were found to predict the progression of CKD. However, studies with simultaneous measurement of mineral bone disorder (MBD)-related factors were scarce. This study aimed to identify factors predicting renal outcome independent of other factors.Design, setting, participants, & measurements This was a prospective cohort study of 738 Japanese predialysis outpatients in the nephrology departments of two hospitals. The outcome was defined as a doubling of serum creatinine or initiation of dialysis.Results Mean estimated GFR (eGFR) was 35 ml/min per 1.73 m 2 . At enrollment, the increase in intact FGF23 with decreasing eGFR was the earliest among changes in MBD-related factors, followed by 1,25-dihydroxyvitamin D decrease, parathyroid hormone increase, and phosphate increase. Conclusions Combined use of two markers is useful for the risk stratification of renal outcome.