Why Do Women Have an Increased Risk of Iron Deficiency?

According to the National Institutes of Health (NIH), most people in the United States have enough iron in their bodies and get sufficient amounts from their regular diets. Some groups of people, including teenage girls and premenopausal and menopausal women are more likely to have trouble getting enough iron strictly from diet alone. In addition, women and teenage girls with heavy bleeding during their periods and women who are pregnant can be iron deficient.

Under typical circumstances, people excrete only small amounts of iron from their bodies on a regular basis, but menstruating women can have more than average iron deficiency because of blood loss, particularly if their periods are heavy.

Iron deficiency in premenopausal women versus menopausal women can be a bit of a chicken and egg situation. Women often feel fatigue or dizziness, a lack of focus, plus many other symptoms of low energy during their periods over many years. This can be due to menstrual blood loss. If iron levels don’t return to normal when a period ends, iron deficiency can continue, and symptoms may continue or get worse over time, persisting into menopause.

Iron Loss During Menstruation and Menopause

Women with heavier blood flow during their periods may have a more difficult time keeping their iron at a healthy level. Diet and exercise affect a woman’s iron levels too. Good sources of iron include lean meats, fish, and poultry, plus beans, seeds, and fortified cereals. A healthy woman between 19-50 years old should have a daily intake of 18 mg of iron, but many women do not get this much iron from their diets. Blood loss during menstruation, especially heavy periods, can exacerbate the lack of dietary iron. Endurance sports, such as running, underlying chronic illnesses such as gastrointestinal disorders, or blood loss due to endometriosis or fibroids can all cause iron deficiency. Even certain types of supplements and foods such as those containing calcium can negatively affect iron levels in women.

Low iron levels do not immediately result in iron deficiency anemia (IDA). IDA develops over time. When iron levels in the blood decrease, ferritin—the blood protein that stores iron—is reduced. This limits the formation of hemoglobin or healthy red blood cells resulting in IDA. Symptoms include fatigue, lack of focus, irritability, and more occur because hemoglobin is not as capable of carrying oxygen to the cells of the body.

Of course, the only way to tell if a woman requires or would benefit from taking iron supplements is to have her iron levels tested by a doctor or health care practitioner.

Iron Deficiency and Pregnancy

Iron considerations for pregnant women are unique. The NIH Office of Dietary Supplements points out that:

“During pregnancy, the amount of blood in a woman’s body increases, so she needs more iron for herself and her growing baby. Getting too little iron during pregnancy increases a woman’s risk of iron deficiency anemia and her infant’s risk of low birthweight, premature birth, and low levels of iron.”

Getting too little iron might also harm the infant’s brain development after birth. Therefore, sufficient iron is important for both the mother and the fetus, as well as for the newborn baby.

A long-term study in the U.S. found that a total of 18 percent of pregnant women had iron deficiency and iron deficiency worsened in each trimester. A little less than 7 percent of women in the first trimester had iron deficiency, increasing to more than 14 percent in the second trimester, and nearly 30 percent in the third trimester. Iron supplements have been shown to prevent IDA in pregnant women —and prevent harm to their newborn babies.

Agencies ranging from The American College of Obstetricians and Gynecologists to the Centers for Disease Control and Prevention acknowledge that iron deficiency puts pregnant women, especially those who are not in good health and/or malnourished, and their infants at risk, and recommends iron supplementation for pregnant women. Once they are evaluated by their obstetrician or health care provider, pregnant women are often prescribed an iron supplement to bring their daily iron intake to 27 mg/day, the amount recommended by The Dietary Guidelines for Americans. Women aged 19-50 normally require 18 mg/day of iron (from all sources), so pregnancy increases that need considerably.

Iron Deficiency in Lactating Women

A women’s body during pregnancy needs more blood and therefore more iron, but healthy new moms typically do not need extra iron once their baby is born, even while breastfeeding. Some women who suffered a lot of blood loss during childbirth or had IDA during pregnancy, especially during the third trimester, may still need to monitor their iron during lactation, but typically do not need supplements. An iron-rich diet with plenty of calories and fluids will help most new mothers produce a healthy supply of breastmilk. Women who are lactating typically require 8-10 mg/day of iron.