title: 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<.001). Dietary Pi regulated the messenger RNA expression of iron-regulated genes, including divalent metal transporter 1, duodenal cytochrome B, and hepcidin. Furthermore, iron concentration in liver tissues was increased by the 1.5% Pi in Con Fe diet. These results suggest that dietary Pi supplementation delays the onset of IDA and increases plasma 2,3-DPG concentration, followed by modulation of the expression of iron-regulated genes.
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Nakao
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan; Department of Health and Nutrition, Faculty of Human Life, Jin-ai University, Echizen City, Fukui 915-8586, Japan; Division of Nephrology, Department of General Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan. Electronic address: yamamoto@jindai.ac.jp.
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Otoki
authors.initials: O
authors.lastname: Nakahashi
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Kotaro
authors.initials: K
authors.lastname: Abe
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Masuda
authors.affiliation: Department of Health and Nutrition, Faculty of Human Life, Jin-ai University, Echizen City, Fukui 915-8586, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Ishiguro
authors.affiliation: Division of Nephrology, Department of General Medicine, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Iwano
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Takeda
authors.affiliation: Department of Clinical Nutrition and Food Management, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima 770-8503, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Taketani
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000517:prevention & control*; D000818:Animals; D019587:Dietary Supplements; D004195:Disease Models, Animal; D007501:Iron / Q000097:blood*; D008297:Male; D010710:Phosphates / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D010710:Phosphates; D007501:Iron
keywords: Anemia; Dietary phosphate; Gene expression; Iron-deficient; Rat