Final answer:
Heme iron is more efficiently absorbed compared to nonheme iron, with dietary iron absorption being influenced by bodily iron levels and enhanced by protein intake.
Step-by-step explanation:
Compared to nonheme iron, heme iron is absorbed more efficiently. Heme iron, derived from animal sources like meat, poultry, and fish, is utilized by the body with greater efficiency than non-heme iron, which comes from plant-based foods. The absorption process includes the reduction of iron to its ferrous form (Fe2+) in the acidic environment of the gastrointestinal tract, aiding in its solubility and absorption.
The body's ability to absorb iron is modulated by various factors including bodily iron levels, with anemic individuals absorbing more iron than those with normal levels. Once absorbed, iron can be stored in the bone marrow, liver, and spleen in the form of ferritin and hemosiderin. Iron transportation across the intestinal cell membranes is mediated by the protein ferroportin.
Enhancers of iron absorption include proteins and certain conditions like pernicious and hypoplastic anemia, while iron absorption can be impaired by the surgical removal of the stomach or a significant part of the intestine.