Iron is essential in hemoglobin, a type of protein that transfers oxygen from the lungs to tissues in the body. Doing so supports metabolism and is necessary for growth, development, normal cellular functioning, and synthesis of some hormones. Because iron deficiency is associated with poor diet, poor absorption disorders, and blood loss, people with iron deficiency usually have a variety of nutrient deficiencies in addition to iron.
Plant: Nuts, beans, vegetables, and fortified grain products. In the United States, Canada, and many other countries, wheat and other flours and infant formulas are fortified with iron.
Animal: Lean meat and seafood.
NOTE: Dietary iron has two main forms: heme and nonheme. Plants and iron-fortified foods contain nonheme iron only, whereas meat, fish, and poultry contain both heme and nonheme iron.
« Frequently used forms of iron in supplements include ferrous and ferric iron salts, such as ferrous sulfate, ferrous gluconate, ferric citrate, and ferric sulfate. Because of its higher solubility, ferrous iron in dietary supplements is more bioavailable than ferric iron.
« Calcium might interfere with the absorption of iron, although this effect has not been definitively established. For this reason, some experts suggest that people take individual calcium and iron supplements at different times of the day.