Nutritional Yeast Ferritin-Iron Complex: A Novel Source of Dietary Iron

Abstract

Iron deficiency anemia (IDA) is the leading nutritional disorder in the world. Iron deficiency (ID) occurs commonly in the US, particularly among children and women and in the elderly. Its impact on quality of life includes decreased cognitive ability and increased fatigue. Thus, there is clearly a need for effective and economical approaches to providing adequate dietary iron. We introduce nutritional yeast ( S. cerevisiae) technologically modified to express human H-ferritin as a potential source of dietary iron. The efficacy of the yeast ferritin complex (YFC) was tested in established rat and monkey models of ID. In the rat model of ID, YFC improved hemoglobin (Hgb), hematocrit (Hct) levels as well as plasma iron and transferrin saturation and liver and spleen iron concentrations. Moreover, the YFC achieved a larger effect on Hgb and Hct with consumption of less iron compared to ferrous sulfate over a similar period. In the monkeys, YFC supplemented diet significantly improved Hgb levels within one month and increased mean corpuscular volume (MCV) by two months. To demonstrate that the Fe in the YFC was utilized by RBCs, we used a labeled isotope approach and found Fe from the ferritin in the monkeys’ RBCs with 5 days of consumption. This is the first attempt to use H-ferritin homopolymer as a nutritional iron source. Previous data from our laboratory and others have established H-ferritin as a significant iron delivery protein to the brain. Thus, H-ferritin appears to have a novel function as an iron delivery protein independent from its cooperation with L-ferritin to form an iron storage protein.