Dietary phosphate supplementation delays the onset of iron deficiency anemia and affects iron status in rats

Abstract Inorganic phosphate (Pi) plays critical roles in bone metabolism and is an essential component of 2,3-diphosphoglycerate (2,3-DPG). It has been reported that animals fed a low-iron diet modulate Pi metabolism, whereas the effect of dietary Pi on iron metabolism, particularly in iron deficiency anemia (IDA), is not fully understood. In this study, we hypothesized the presence of a link between Pi and iron metabolism and tested the hypothesis by investigating the effects of dietary Pi on iron status and IDA. Wistar rats aged 4 weeks were randomly assigned to 1 of 4 experimental dietary groups: normal iron content (Con Fe) + 0.5% Pi, low-iron (Low Fe) + 0.5% Pi, Con Fe + 1.5% Pi, and Low Fe + 1.5% Pi. Rats fed the 1.5% Pi diet for 14 days, but not for 28 days, maintained their anemia state and plasma erythropoietin concentrations within the reference range, even under conditions of low iron. In addition, plasma concentrations of 2,3-DPG were significantly increased by the 1.5% Pi diets and were positively correlated with plasma Pi concentration ( r  = 0.779; P