Category: mineral
Aliases: P, Phosphate, Pi
Essential dietary macromineral. Backbone of ATP/ADP, nucleic acids and phospholipid membranes; ~85% resides in bone as hydroxyapatite. Absorbed via sodium-dependent NaPi-IIb cotransport (upregulated by calcitriol); serum level set by renal reabsorption under PTH and FGF23 control.