Please Pass That Woman Some Calcium and Iron
Willis, Judith, FDA Consumer
This is the last article in a three-part series on women and nutrition. The first article discussed pregnancy; the second, energy needs and eating patterns.
A pale young woman complains that her head aches with fatigue. An old woman, bent over, walks haltingly with a cane.
Though these examples of iron deficiency anemia and osteoporosis are extreme, they do portray health problems that are more common in women than in men. These and other problems sometimes can be prevented or alleviated by adequate nutrition. The best way to accomplish this is through an educated choice of foods. As discussed in the second part of this series, women usually eat less than men, thus they have a greater need for food that is as nutrient-dense as possible.
Although women's and men's requirements for most vitamins and minerals are similar, there are situations in which women's needs for certain nutrients exceed men's. It is well-known, for example, that women of childbearing age need more iron. Calcium is another nutrient that may be more crucial to women. The type of contraception a woman uses also may affect her needs for specific vitamins and minerals.
A women's greater need for iron is directly related to her childbearing function. The first article in this series, "All About Eating For Two," in the March 1984 FDA Consumer, discussed the pregnant woman's need for iron. In non-pregnant women, the monthly blood loss during menstruation may cause an iron deficiency. A loss of 15 to 20 milligrams (mg) of iron occurs during an average menstrual period. However, about 10 percent of all women are believed to lose twice that much. This includes many wearing intrauterine devices (IUDs). Women who use oral contraceptives (OCs) may not have as much of an iron deficiency because blood loss is often reduced with OC use.
As iron is depleted, iron deficiency anemia can develop. The symptoms include pallor, fatigue and headaches. Clinically, iron deficiency anemia in non-pregnant women is defined as a hemoglobin count below 12. Depletion of iron reserves that has not reached the anemic stage is a less severe condition estimated to occur in many healthy pre-menopausal women. It is rare in healthy men. Increasing evidence indicates that even mild depletion of iron reserves (before anemia sets in) may be related to decreased physical and mental performance.
Before a woman takes iron supplements, her degree of iron deficiency should be diagnosed by a physician because some conditions with the same symptoms actually-require less iron, and in such cases an excess of iron can cause serious problems.
A wise choice of foods and a knowledge of how iron absorption works can help prevent iron deficiency.
There are two main types of dietary iron: heme and non-heme. Heme iron is found only in meat (including fish and poultry) and is more efficiently absorbed by the body. Non-heme iron comes from other iron-containing foods. Eating meat with non-heme iron foods improves the absorption of the non-heme iron by the body. Viatmin C (ascorbic acid) also aids iron absorption. A person attempting to obtain the optimum amount of iron would be wise to eat foods rich in vitamin C, such as citrus fruits, along with iron-rich foods.
Iron absorption varies with the body's need and with certain diseases. People deficient in iron absorb a higher proportion, while those who have unusually large stores of iron absorb less.
A woman needs about 1.8 milligrams of iron daily. Because people absorb only about 10 percent of the iron in food, the National Research Council recommends that women consume 18 milligrams of iron in their daily diets. This can be obtained from a variety of foods (see chart).
Some food components make absorption of iron more difficult. For example, some elements of tea (tannic acid and phytates) interfere with iron absorption. Some fruits, vegetables and whole grains also contain phytates. …