During childhood (ages 9 to 13) both boys and girls need about 8 milligrams of iron daily. As teens grow, their muscle mass increases and blood volume expands, increasing their need for iron, so the recommendation jumps to 15 milligrams of iron daily for girls ages 14 to 18, and 11 milligrams daily for boys ages 14 to 18.
Despite the abundance of iron in the United States food supply through natural, enriched and fortified food sources, teens may be consuming less of this mineral than their developing bodies require. Adolescent girls, especially, tend to have lower intakes of foods that provide iron. Children and adolescents from food-insecure households are at greater risk of not getting enough iron than their peers who have easier access to food. Girls are also at increased risk of iron deficiency due to iron loss during menstruation. If teens are following calorie-restrictive diets to lose or manage weight, that may affect iron intake, and vegetarian or vegan teens may also be at risk of not getting enough iron.
What Iron Does in the Body
Iron plays a significant role in many diverse functions because it helps the blood carry oxygen to the lungs, muscles and all parts of our bodies. Because of this role, it also is involved in brain function and helps keep our immune system strong.
An iron deficiency may not show any signs or symptoms or it may result in several, so it’s important your child's pediatrician evaluates them. One common sign is fatigue. Other symptoms may include shortness of breath; frequent colds and infections; poor concentration; pale skin; lightheadedness; irregular heart rate; headaches; and thin, brittle and concave-shaped nails. Deficient teen athletes may have lackluster training sessions and experience fatigue during workouts.
How to Get More Iron
Iron comes from a variety of foods: meat, poultry and seafood, as well as beans, nuts, enriched grain products and leafy green vegetables.
Animal sources of iron (which contain heme iron) are more easily absorbed by the body, while plant sources (non-heme iron) should be eaten with a vitamin C source to help increase its absorption. For example, serve iron-fortified cereals with strawberries, and cook beans with tomatoes in a chili. Cooking food in a cast iron pan also can increase iron content.
You can also check the Nutrition Facts Label for the amount of iron that a food provides based on the serving size that is listed. The Percent Daily Value (%DV) is a quick way to identify good sources. Look for a higher %DV of iron when comparing foods, if more iron is needed.
Some foods and beverages may cause the body to absorb less iron when eaten close together. A registered dietitian nutritionist can develop an eating plan that's right for your teen and includes good sources of iron with meals and snacks.
Taking an iron supplement to correct an iron deficiency should be done only under a physician's supervision and monitored with follow-up blood tests since high doses of iron from supplements can be harmful, especially for young children.