Protein depletion and iron deficiency in rats.

Rats were fed on low iron diets containing 5, 10 and 30% protein. All animals demonstrated typical iron deficiency. Body size was reduced as protein intake decreased. The severity of anemia was related to the growth of the animal. Erythropoiesis appeared to be stimulated in proportion to the severity of the anemia. Iron absorption from the iron-deficient diet appeared unaffected by the associated protein deficiency. When doubly depleted animals were refed with iron, there was active red blood cell production despite the protein-depleted state, whereas with protein refeeding there was resumption of growth and increased anemia. These studies demonstrate the inverse relationship between protein and iron deficiency states when they coexist.