Learning Can Suffer From Iron Deficiency

If your high-school-age daughter is feeling tired and unenthusiastic, she could be suffering from iron deficiency, the most prevalent nutritional disorder in the world. In the United States, up to 25 percent of all adolescent girls are affected. And the problem cuts across all socioeconomic levels.

Now, a study from Johns Hopkins researchers suggests iron deficiency may also limit memory and verbal learning, which could affect school performance, too.

Parents have to ask for special tests if they want an accurate evaluation of their daughters’ iron status. Ordinarily, several tests are used to diagnose iron deficiency anemia. The most common test is for hemoglobin levels. If it is in the normal range, the patient is declared “fine.”

In the Hopkins study, all the girls had normal hemoglobins, but their separate test results for storage iron - called serum ferritin - were below normal. So, although they were not yet anemic, they were iron deficient.

Researchers treated half the iron-deficient girls with iron supplements and half with placebos. Those on supplements showed immediate improvement in iron status, which then improved their performance on some of the tests of verbal learning and memory.

Adolescent girls are at risk for iron deficiency for several reasons. They are in a period of rapid growth where their own bodies demand additional iron to create new tissue and additional blood. They are beginning their menstrual periods, so they are losing iron every month. At the same time, many girls are restricting their food intake, which limits the amount of iron they consume. And many have given up red meat, the best dietary source of iron.

Adding a small amount of lean meat, poultry or fish to a meal gives a double bang for the nutritional buck. First, heme iron comes from those animal foods, and heme iron is more easily absorbed than the iron from plant foods. Second, the heme iron increases the amount of iron absorbed from plant foods like beans, grains and vegetables. It’s as simple as this: You get more iron from beans when you eat them with meat than you do when you eat them alone.

But I’m meeting more and more teen-age girls who have gone vegetarian and will not eat meat. Parents, take heart. Eating foods high in vitamin C along with plant foods also increases iron absorption. That makes a good argument for well-balanced meals, and it’s easy to do:

Add a glass of orange juice to a breakfast of iron-fortified cereal (cream of wheat is outstanding, but cold cereals like Total are fine, too) and skim milk.

Have a kiwi fruit, orange or tangerine for dessert after a lunch of split pea soup and a bagel.

Enjoy a fresh spinach and tomato salad with a dinner of black beans and rice.

Fruits high in vitamin C include kiwi, oranges, grapefruit, tangerines, mangoes, strawberries, raspberries and blueberries, orange and grapefruit juice and cranberry juice cocktail. High C vegetables include broccoli, cauliflower, sweet green or red peppers, spinach, tomatoes and tomato products, brussels sprouts, and kale, collard, turnip and mustard greens.

Drinking coffee or tea with meals decreases iron absorption, so limit those beverages to more than one hour before meals or two hours after.

A daily vitamin supplement that meets 100 percent of the RDA for vitamins and minerals is an inexpensive and safe way to raise daily iron intake to normal. The least expensive brand will do.