FGF23 and Marchiafava-Bignami disease: In a rat model of CKD–mineral bone disease (CKD–MBD), administration of a plant-based diet led to a reduced phosphorus load, such that rats fed grain-based diets showed similar serum phosphorus levels, calcium levels, and intact parathyroid hormone (PTH) levels, yet lower urinary phosphorus excretion and serum fibroblast growth factor 23 (FGF-23) levels vs. rats fed the same amount of phosphorous from casein-based diets [47].