The effects of an adequate supply of vitamin A and iron, in comparison with diets low or absent in vitamin A and low in iron, on the mRNA expression of some biomarkers of iron homeostasis as hepcidin (Hamp), transferrin receptor-1 (Tfrc), iron regulatory protein-2 (Ireb2) and ferritin (Fth1) in rats were investigated. 35 male Wistar rats were randomly divided into 5 dietary groups: control, sufficient in iron and insufficient in vitamin A (FesvAi), sufficient in iron and depleted in vitamin A (FesvAd), insufficient in iron and sufficient in vitamin A (FeivAs) and insufficient in both iron and vitamin A (FeivAi). After 6 weeks rats showed no significant effects of variations in vitamin A on the expression of Hamp relative to the control group (FesvAi: 1.37-fold; FesvAd: 1.22-fold); however, iron deficiency showed significant reduction on it relative to the control group (FeivAs: 71.4-fold, P = 0.0004; FeivAi: 16.1-fold, P = 0.0008). Vitamin A deficiency (FesvAd) affects expression of Fth1 independent of low dietary iron in spleen (0.29-fold, P = 0.002) and duodenum (5.15-fold, P = 0.02). Variations of dietary iron and vitamin A showed significant effects relative to the control group for expression of Tfrc in spleen (FesvAd: 0.18-fold, P = 0.01; FeivAs: 0.24-fold, P < 0.0001; FeivAi: 0.42-fold, P = 0.014), Ireb2 in spleen (FeivAs: 3.7-fold, P < 0.0001; FeivAi: 2.9-fold, P < 0.0001) and Ireb2 in duodenum (FeivAs: 2.68-fold, P = 0.012; FeivAi: 2.60-fold, P = 0.014). These results show that vitamin A and iron must be supplied together to regulate some of the main biomarkers of iron metabolism as a strategy to reduce prevalence of iron deficiency anemia.
Keywords: anemia; hepcidin; retinol; vitamin A deficiency.