Iron Deficiency - Food Sources of Iron

Food Sources of Iron

Mild iron deficiency can be prevented or corrected by eating iron-rich foods and by cooking in an iron skillet. Because iron is a requirement for most plants and animals, a wide range of foods provide iron. Good sources of dietary iron have haem-iron as this is most easily absorbed and is not inhibited by medication or other dietary components. Three examples are red meat, poultry and insects. Non-haeme sources do contain iron, though it has reduced bioavailability. Examples are lentils, beans, leafy vegetables, pistachios, tofu, fortified bread, and fortified breakfast cereals.

Iron from different foods is absorbed and processed differently by the body; for instance, iron in meat (heme iron source) is more easily absorbed than iron in grains and vegetables ("non-heme" iron source), but heme/hemoglobin from red meat has effects which may increase the likelihood of colorectal cancer. Minerals and chemicals in one type of food may also inhibit absorption of iron from another type of food eaten at the same time. For example, oxalates and phytic acid form insoluble complexes which bind iron in the gut before it can be absorbed.

Because iron from plant sources is less easily absorbed than the heme-bound iron of animal sources, vegetarians and vegans should have a somewhat higher total daily iron intake than those who eat meat, fish or poultry. Legumes and dark-green leafy vegetables like broccoli, kale and oriental greens are especially good sources of iron for vegetarians and vegans. However, spinach and Swiss chard contain oxalates which bind iron making it almost entirely unavailable for absorption. Iron from nonheme sources is more readily absorbed if consumed with foods that contain either heme-bound iron or vitamin C. This is due to a hypothesised "meat factor" which enhances iron absorption.

Following are two tables showing the richest foods in heme and non-heme iron. In both tables, foods serving size may differ from the usual 100g quantity for relevancy reasons. Arbitrarily, the guideline is set to 18 mg, which is the USDA Recommended Dietary Allowance for women aged between 19 and 50.

Iron deficiency can have serious health consequences that diet may not be able to quickly correct, hence an iron supplement is often necessary if the iron deficiency has become symptomatic.