Lean beef is rich in iron—3 ounces contains about 3 milligrams, or about 15 percent of your daily needs. (Clams, oysters and poultry are also good sources containing 24, 5 and 2 mg per 3 ounces, respectively.) You need iron to transport oxygen from your lungs to the cells in your body. During your childbearing years, your recommended intake is highest at 18 mg/day because you need to replace what’s lost each month through menstruation—the only other time you need more is during pregnancy at 27 mg/day.
Other ways to get iron: It’s in beans (up to 13 mg per 3/4 cup), dark leafy greens (1/2 cup cooked spinach = 3 mg) and dried fruit, but in these foods it's in a form that your body can’t absorb as easily. You can boost your iron absorption by pairing them with a vitamin C-rich food, such as oranges and sweet potatoes. Fortified products, such as breads, cereals and breakfast bars, also contribute significant amounts of iron (some fortified cereals can contain up to 24 mg of iron per 1-cup serving), but again in a form that’s not as easily absorbed alone.