Q: I’m a healthy 40 year-old woman, but I have trouble keeping my iron level up. I don’t eat red meat. Can I get enough iron from other foods without taking a supplement?
Women who lose iron each month during menstruation are particularly vulnerable to running low on the mineral, the most common nutrient shortfall in the world. But they aren’t the only ones at risk.
If you’re pregnant, a vegetarian, a frequent blood donor or if you’re on long-term acid-blocking medication (stomach acid assists in iron absorption), you’re also at risk.
While red meat has a lot of iron in a form that’s easily absorbed by the body, there are plenty of other foods that can help shore up your iron stores. To maximize your body’s iron uptake from some of these foods, though, a few dietary tweaks are required.
What iron does
Iron is needed to make hemoglobin, a component of red blood cells that transports oxygen from your lungs to organs and tissues throughout the rest of your body. The mineral is also used to maintain healthy cells, skin, hair and nails, make hormones and connective tissue and aid proper nerve function.
If you don’t consume enough iron, eventually your body can’t make enough oxygen-carrying hemoglobin causing iron deficiency anemia. Symptoms include fatigue, shortness of breath during exercise, pale skin, hair loss, brittle nails, headache, dizziness and rapid heartbeat.
Having too little iron can affect your brain and immune system, too. Poor work performance, difficulty concentrating and increased risk of infections are other signs of iron deficiency.
Animal versus plant iron
Food contains two forms of iron. Heme iron, attached to the protein hemoglobin in animal foods such as meat, fish, seafood and eggs, is easily absorbed by the body.
Iron in plant foods such as beans and lentils, soy, nuts, whole grains and vegetables is called non-heme iron. It’s not attached to hemoglobin, making it harder for the body to absorb. Non-heme iron is also added to iron-enriched breakfast cereals and breads.
There are ways, however, to increase the amount of non-heme iron your body absorbs.
You’ll get more iron from plant foods if you eat them cooked (vegetables), sprouted (breads, grains, beans, lentils), soaked (nuts) and fermented (tempeh) since these preparation methods release iron from phytates, natural compounds in plants that bind iron.
Including a vitamin C-rich food (e.g., sweet bell pepper, broccoli, cauliflower, tomato sauce, strawberries, kiwifruit, citrus fruit) in a plant-based meal will also boost non-heme iron absorption. The acidity of the vitamin converts iron to a form that’s more readily absorbed.
Tannins in coffee and tea reduce iron absorption, so it’s best to drink them between meals. Calcium also interferes with iron absorption; take calcium supplements a few hours before or after an iron-rich meal.
Iron beyond beef
Your daily iron requirement depends on your gender and age. Women aged 19 to 50 need 18 mg of iron each day; during pregnancy daily iron requirements increase to 27 mg. Adult men and postmenopausal women require 8 mg.
Vegans, who rely on plant-based sources, require more iron. Premenopausal women need 32 mg each day; older women and men should consume 14 mg.
While red meat is a good source of easily-absorbed heme iron, you’ll find more in clams, oysters and mussels. Dark chicken and turkey meat provides a little more iron than white meat.
When it comes to plant foods, exceptional sources of non-heme include edamame, lentils, quinoa, pumpkin and sunflower seeds, cashews, tofu and dark chocolate. Cooked spinach is an excellent source of iron; it also contains vitamin C, a nutrient that enhances iron absorption.
What about supplements?
Menstruating women may benefit by taking a multivitamin and mineral supplement containing 10 to 18 mg of iron, in addition to dietary sources, to help maintain sufficient iron stores. Pregnant women should take a supplement with 27 mg of iron.
Unless you have an iron deficiency, taking a single iron supplement can be harmful since iron builds up in the organs and can have damaging effects.
People with an inherited condition called hemochromatosis absorb too much iron and should avoid iron-containing multivitamins and single iron supplements.
Leslie Beck, a Toronto-based private practice dietitian, is Director of Food and Nutrition at Medcan.
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