There are a number of sources of iron which can be used to supplement the diet, ensuring that you get enough iron. Women need around 18 milligrams of iron every day, while men and post-menopausal women need 8 milligrams. Some agencies recommend that vegetarians consume more iron, for reasons which will be discussed below, and iron consumption should never exceed 45 milligrams per day.

Two types of iron can be found in food. Foods from animal sources contain heme iron, a type of iron which is easy for the body to absorb. Vegetarian sources of iron have non-heme iron, a form of iron which cannot be absorbed as easily. For this reason, vegetarians may need to eat more iron to ensure that they absorb enough. Iron absorption can be increased by consuming sources of iron with vitamin C.

Red meat, especially liver, is one of the best sources of iron. A single serving of liver contains around seven milligrams of iron, with red meat in general containing between two and four milligrams of iron a serving. White meats contain some iron, typically half a milligram to three milligrams a serving, and eggs are also good sources of iron.

Non-heme sources of iron include kidney beans, with three milligrams a serving, along with soy beans, dark leafy greens like spinach, dried fruit, lentils, and grains such as wheat and oats. As a general rule, non-heme sources of iron contain half a milligram to two milligrams a serving. It is also possible to eat various foods such as cereals which have been fortified with iron, and to take iron supplements. Iron supplements should be taken with food to increase absorption, and people should be aware that the body can only absorb so much at once, so it's better to space supplements out over the course of the day, rather than to take them all at once.

Lack of iron leads to anemia, a very common nutritional deficiency which can have serious consequences. People with anemia may feel faint or tired, and they often experience dulled skin and hair, headaches, rapid heartbeats, dizziness, shortness of breath, and abdominal pain. Some people may develop pica, a condition characterized by a tendency to eat things which are dangerous or inappropriate, such as dirt. Pica appears to develop in response to nutritional deficiencies, with the body seeking out the most likely sources of the nutrients it needs.