FGF23 and hyperparathyroidism: In an experimental study in uremic rats, rats in the sham-surgery group with preserved parathyroid glands showed high PTH and high FGF-23 during renal failure induced by feeding the adenine high-phosphorus diet, compared to control rats with destroyed parathyroid glands, implicating that hyperparathyroidism secondary to CKD could induce increased serum levels of FGF-23 (Lavi-Moshayoff et al., 2010).