Modulation of Intestinal Phosphate Transport in Young Goats Fed a Low Phosphorus Diet.

The intestinal absorption of phosphate (P) takes place transcellularly through the active NaPi-cotransporters type IIb (NaPiIIb) and III (PiT1 and PiT2) and paracellularly by diffusion through tight junction (TJ) proteins. The localisation along the intestines and the regulation of P absorption differ between species and are not fully understood. It is known that 1,25-dihydroxy-vitamin D (1,25-(OH)D) and phosphorus (P) depletion modulate intestinal P absorption in vertebrates in different ways.