Iron is a mineral essential for the production of blood. Iron in the blood is called hemoglobin, and it transports oxygen throughout the body. Iron in the muscles is called myoglobin; it is responsible for storing, releasing and transporting oxygen. It is best to get dietary iron from meat, or heme, sources, instead of plant sources or supplements. However, the advantage of getting iron from plant sources is that it is regulated by the body better and causes less damage. The recommended dietary allowance, or RDA, of iron is 8 milligrams for men 19 and older. For women in the same age range, the RDA is 18 to 27 milligrams -- the higher end is for women who are pregnant or lactating.
The liver is an organ rich in blood, making it high in iron. A 4-ounce piece of pork liver contains 26.33 milligrams of iron, which is 146 percent of the daily value, or DV. One chicken liver contains 5.67 milligrams of iron, and one slice of fried beef liver has 5 milligrams of iron, or 28 percent of the DV.
Beef and Lamb
Beef and lamb are good sources of heme iron. A 3-ounce serving of lean beef or lamb tenderloin contains 3.1 milligrams of iron.
A serving of 10 clams contains 26.5 milligrams of iron. That is 147 percent of the DV. One medium-sized oyster contains 2.3 milligrams of iron, which means that a serving of 10 contains 23 milligrams of iron. Octopus, also considered a mollusk, has 8.11 milligrams of iron in a 3-ounce serving, providing 45 percent of the daily value.
Dark, Leafy Green Vegetables
Spinach, Swiss chard and turnip greens contain a lot of iron. One cup of cooked spinach has 6 milligrams of iron, or 36 percent the daily value. There are 3.96 milligrams of iron in 1 cup of cooked Swiss chard, providing 22 percent of the DV, and 1.15 milligrams in a cup of cooked turnip greens.
A handful of 142 pumpkin seeds has 23 percent of the DV of plant iron. A 1-ounce serving of pumpkin or squash seeds has 4 milligrams of iron.
Beans and Lentils
Beans are a source of plant heme. White beans contain 1 milligram of iron in 2 tablespoons. Chickpeas, lima beans, kidney beans and pinto beans contain approximately 4 percent of the daily value of iron in a 2-tablespoon serving.
Whole Grains and Fortified Cereals
Whole grains and fortified cereals also contain iron. One cup of cooked oatmeal has 12 percent of the DV of iron. A cup of cooked quinoa has 2.8 milligrams of iron, or 15 percent of the daily value. Many of the fortified cereals on the market have up to 140 percent of the DV of iron in a 1-cup serving.
Iron can be found in your favorite chocolate bar, provided it is the dark variety. Your average candy bar, at 1.5 ounces, provides 6 percent of the daily value of iron. A square of dark chocolate, a more concentrated piece, has 5 milligrams of iron, which is 28 percent of the DV.
Eighteen cashews, which is about 1 ounce, have 1.7 milligrams of iron, which is 9 percent of the daily value. Hazelnuts, peanuts, almonds and pistachios provide 7 percent of the DV in 1 ounce.
Tofu is a nonmeat iron source as well. One-fourth of a block of tofu has 2.2 milligrams of iron, which is 12 percent of the DV of iron.