This study examined whether or not the iron that is accumulated in the recombinant microbes that produce ferritin is bioavailable to rats with iron deficiency. Rats induced with iron deficiency were treated with iron preparations of $Fe(NH_4)_2(SO_4)_2$, horse spleen ferritin, control yeast, and ferritin-producing recombinant yeast for 14 days. The bioavailability of iron was examined by measuring hemoglobin concentration, hematocrit value, and tissue iron stores. Differences between dietary groups were determined by one-way ANOVA, at the level of significance p<0.05. Based on hemoglobin concentration and hematocrit value, iron in $Fe(NH_4)_2(SO_4)_2$, horse spleen ferritin, and ferritin-producing yeast were bioavailable in rats and cured iron deficiency. The efficacy of ferritin and ferritin-producing yeast was confirmed in establishing tissue iron stores after the induction of iron deficiency. The iron sources of ferritin and the ferritin-producing yeast seemed to be as effective for the recovery from iron deficiency as the iron compounds of ferric citrate and ferrous ammonium sulfate. The results suggest that the iron stored in ferritin of the recombinant yeast is bioavailable, and that the recombinant yeast may contribute widely as a source of iron to resolve the global problem of iron deficiency.