What foods provide Iron?
There are two forms of dietary Iron: heme and nonheme. Iron in meat, fish, and poultry is found in a chemical structure known as heme. Heme Iron is absorbed very efficiently by your body (1,3-4). Iron in plants such as lentils and beans are arranged in a different chemical structure called nonheme Iron. Nonheme Iron is not as well absorbed as heme Iron (1,3-4). Flours, cereals, and grain products that are enriched or fortified with Iron are good dietary sources of nonheme Iron (5). The addition of Iron to infant formulas, cereals, and grain products has been credited with improving the Iron status of millions of infants, children, and women. The tables of selected food sources of heme and nonheme Iron suggest many dietary sources of Iron.

What affects Iron absorption?
Iron absorption refers to the amount of dietary Iron that your body obtains from food. Healthy adults absorb about 15% of the Iron in their diet, but your actual absorption is influenced by your body's Iron stores, the type of Iron in the diet, and by other dietary factors that either help or hinder Iron absorption (1, 3, 6-9).

The greatest influence on Iron absorption is the amount stored in your body. Iron absorption significantly increases when body stores are low. When Iron stores are high, absorption decreases to help protect against Iron overload (1,3).

Absorption of heme Iron is very efficient and not significantly affected by the composition of your diet (1). Only 1% to 7% of the nonheme Iron in vegetable staples such as rice, maize, black beans, soybeans and wheat is absorbed when consumed as a single food (3). However, dietary factors can significantly improve nonheme Iron absorption (1,3, 6-9). Meat proteins and vitamin C will improve the absorption of nonheme Iron (1,10). Diets that include a minimum of 5 servings of fruits and vegetables daily, as recommended by the Food Guide Pyramid, should provide plenty of vitamin C to boost nonheme Iron absorption. Calcium, polyphenols and tannins found in tea, and phytates, which are a component of plant foods such as legumes, rice and grains, can decrease the absorption of nonheme Iron (1, 11-15). Some proteins found in soybeans also inhibit nonheme Iron absorption (1, 16). Most healthy individuals can maintain normal Iron stores when the diet provides a wide variety of foods as suggested by the Food Guide Pyramid. It is most important to include foods that enhance nonheme Iron absorption when total daily Iron intake does not meet the RDA, when Iron losses are exceptionally high, or when no heme Iron is usually consumed.