FIGURE 2.

Lowering FGF23 by decreasing P load. P is ingested as organic or inorganic (additive to natural diet) forms. P is released by luminal phosphatases and absorbed via paracellular and transcellular routes. 1. Dietary restriction of total P intake or P modification, switching from high to low bioavailable P (from inorganic to organic P). 2. Luminal P binders can be divalent metal (Ca²⁺, Mg²⁺ and Fe²⁺), trivalent metal (Al³⁺ and La³⁺) and anion exchange polymers. 3. Inhibition of transcellular transport by direct or indirect inhibition of NaPi-2b. 4. Blocking paracellular transport is achieved by lumen-restricted inhibition of apical NHE3 with secondary effects on paracellular permeability.