Vitamin B12 deficiency-induced increase of osteoclastic bone resorption caused by abnormal renal resorption of inorganic phosphorus via Napi2a

Vitamin B 12 deficiency is a risk factor for bone disorders via mechanisms not fully understood. In this study, an increase in serum inorganic phosphorus (Pi) concentrations was associated with a vitamin B 12 deficiency. Napi2a, a renal cotransporter for Pi reabsorption, accumulated on plasma membranes in a vitamin B 12 deficiency suggests that vitamin B 12 plays an important role in Pi homeostasis.