Iron is a mineral that is found in every living cell. Iron exists in two forms—heme and nonheme. Heme iron is part of the hemoglobin and myoglobin molecules in animal tissues. About 40% of the iron in meat is in the heme form. Nonheme iron comes from animal tissues other than hemoglobin and myoglobin and from plant tissues. It is found in meats, eggs, milk, vegetables, grains, and other plant foods. The body absorbs heme iron much more efficiently than nonheme iron. Much of the iron in our diet comes from foods, such as breads and cereals that are fortified with this mineral. Worldwide, iron deficiency anemia is the most common form of malnutrition.
Iron's functions include:
- In hemoglobin, carrying oxygen to cells throughout the body
- In myoglobin, holding oxygen within the cells, especially heart and skeletal muscle cells
- Forming collagen, which is the major protein that makes up connective tissue, cartilage, and bone
- Helping fight infection by synthesizing certain enzymes needed for immune function
- Helping convert beta carotene to vitamin A
- Helping make amino acids, which are the building blocks of protein
- Aiding drug detoxification pathways in the liver
- Forming part of an enzyme that is essential for the production of several neurotransmitters
- Synthesizing cellular components that are important to metabolism
Last reviewedAugust 2012by Brian Randall, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.