FGF23 and Abnormal renal physiology: In addition, renal dysfunction was associated with significant elevations in the plasma levels of both intact FGF23 (353 ± 58 vs. 7382 ± 2014 pg/mL, p < 0.05; Figure 1F) and c-terminal FGF23 (187 ± 34 vs. 3075 ± 858 pg/mL, p < 0.05; Figure 1G).