Method of reducing phosphate absorption by administering orally an IgY anti-intestinal sodium phosphate cotransporter type 2B antibody

A method of reducing phosphate absorption in a human or non-human animal subject at risk of developing or having developed hyperphosphatemia, the method comprising the step of:

• administering orally to the subject an anti-intestinal sodium phosphate cotransporter type 2B (Npt2B) antibody that binds to an epitope within amino acids 234-362 of SEQ ID NO:1 in an amount effective to reduce or maintain the serum phosphate concentration in the subject at a level of or lower than 150% of a maximum physiological serum phosphate concentration of 5.5 mg/dl.

A method of reducing phosphate absorption in a human or non-human animal subject at risk of developing or having developed hyperphosphatemia, the method comprising the step of:

• administering orally to the subject an anti-intestinal sodium phosphate cotransporter type 2B (Npt2B) antibody that binds to an epitope within amino acids 429-485 of SEQ ID NO:1 in an amount effective to reduce or maintain the serum phosphate concentration in the subject at a level of or lower than 150% of a maximum physiological serum phosphate concentration of 5.5 mg/dl.

A method of reducing side effects of vitamin D therapy in a human subject comprising the step of:

• administering orally to the subject (a) a vitamin D compound and (b) an anti-intestinal sodium phosphate cotransporter type 2B (Npt2B) antibody that binds to Npt2B of SEQ ID NO:
• 1 in an amount effective to reduce hyperphosphatemia induced by vitamin D therapy, to maintain the serum phosphate concentration in the subject at a level of or lower than 150% of a maximum physiological serum phosphate concentration of 5.5 mg/dl.