When my 35-year-old friend May complained of extreme fatigue, I was not surprised. She did look pale and drawn, as you might expect for the mother of a four-month-old baby and three older children.
Tara, May’s 13-year-old daughter, was complaining of fatigue, too, and I thought the teenager looked a little pale under her bottle tan.
Of course! It made sense that both May, a lactating mother, and Tara, a teenager, were probably suffering from iron deficiency, especially since both of them had recently become vegetarians.
I suggested they check with their health care provider and get a simple blood test, which confirmed that both of them had low levels of iron in their blood. Called iron deficiency anemia, in this disorder the red blood cells are incapable of carrying sufficient oxygen to body tissues. No wonder low iron intake can make us feel tired and draggy.
May was at particularly high risk for iron deficiency anemia because of recent childbirth and her body’s increased need for iron because she was breastfeeding. Tara, who had recently reached puberty, was also at increased risk because of blood loss through menstruation.
Both increased their risk by avoiding animal protein, a primary source of dietary iron, although iron is available in small amounts from legumes, leafy green vegetables, and fortified cereals.
They are not alone. According to the Canadian National Institute of Nutrition, up to 39 percent of teenage girls and 20 percent of all women of childbearing age suffer from some sort of iron deficiency.
“Iron deficiency is the most common single nutrient deficiency in the world,” says nutrition specialist Shari Lieberman, PhD, co-author with Nancy Bruning of The Real Vitamin and Mineral Book (Avery, 2003).
Not only are women more susceptible to iron deficiency, it is also harder for them to take in enough iron-rich food with a balanced diet to meet the recommended daily intakes of 8 mg for men, 18 mg for women, and 27 mg for pregnant women. The US National Institutes of Health estimates that about half of all pregnant women worldwide are iron deficient.
Many children suffer from iron deficiency as well, and many toddlers under the age of three are lacking the necessary 7 mg of iron per day; many infants under the age of one year are lacking the necessary 11 mg per day. Breastfed babies need less iron because iron is absorbed three times better when it is in breast milk.
The reason for most deficiencies is that only about 10 to 15 percent of the iron in food we eat is absorbed by the body. That means we get less than 2 mg of iron in each serving of chicken livers that supposedly contain 12.8 mg of iron (see chart).
Very few Canadian men and boys are iron deficient because they absorb enough iron from a diet that includes red meat. Iron supplementation in a good multivitamin and mineral supplement is an easier answer for most women and children.
Iron sulphate is the most common form of iron supplement found on the market, although Dr. Lieberman warns it can irritate the digestive tract. She recommends iron glycinate, iron fumarate, and iron gluconate, since they are less irritating and less likely to cause constipation, iron’s side effect.
All it took for May and Tara to regain their energy was a visit to their health care provider and some simple iron supplements, plus a little more soy protein in their vegetarian diets. Their blood iron levels are now monitored yearly to ensure the amount of iron they take is sufficient.
|Food||mg per serving||Percentage of daily requirement|
|chicken liver, cooked, 3-1/2 oz/100g||12.8||70|
|soybeans, boiled, 1 cup/250 mL||8.8||50|
|lentils, boiled, 1 cup/250 mL||6.6||35|
|beans, kidney, boiled, 1 cup/250 mL||5.2||25|
|oysters, sautéed, 6 pieces||4.5||25|
|beans, navy, boiled, 1 cup/250 mL||4.5||25|
|beef, chuck, lean only, braised, 3 oz/85g||3.2||20|
|clams, sautéed, 3/4 cup/180 mL||3.0||15|
|beef, tenderloin, roasted, 3 oz/85g||3.0||15|
|Source: US National Institutes of Health|