Iron Deficiency Anemia
Iron is essential to multiple metabolic processes, including oxygen transport (e.g., critical to muscle and brain functioning), DNA synthesis, and electron transport. Iron balance in the body is carefully regulated to guarantee that sufficient iron is absorbed in order to compensate for body losses of iron. Either inadequate intake of absorbable dietary iron or excessive loss of iron from the body can cause iron deficiency. Menstrual losses are highly variable, ranging from 10 to 250 mL (4 to 100 mg of iron) per menses. Women require twice the iron intake of men to maintain normal stores, and can expect to lose approximately 500 mg of iron with each pregnancy without careful attention to adequate dietary intake and supplementation. Iron deficiency anemia occurs when all of the body’s iron stores have been entirely depleted. This chapter focuses on the iron needs of the pregnant and lactating woman.
Iron deficiency is the most common nutritional deficiency worldwide, affecting 20% of the world’s population. It is considered the most common health problem faced by women worldwide, adjusted for all ages and economic groups. Poor socioeconomic status does, however, further increase the risk of iron deficiency anemia. It is estimated that worldwide, 20% to 50% of all maternal deaths are related to iron deficiency anemia.
During pregnancy the blood volume expands by about 35% to 50%, with additional iron required to meet the needs of the fetus, placenta, and increased maternal tissue. In the second and third trimesters, iron requirements increase to three times the nonpregnant needs. Women who do not supplement iron during pregnancy are usually unable to maintain adequate iron stores throughout and are at increased risk for developing iron deficiency anemia. Women who have a history of iron deficiency anemia prior to pregnancy, low iron stores at the onset of pregnancy, or those with heavy menstrual blood loss, are at further risk for anemia during pregnancy. Iron deficiency anemia decreases quality of life to due to symptoms of fatigue, weakness, loss of appetite, and increased susceptibility to infection (see Symptoms), and increases the risk of a number of problems including severe anemia from normal blood loss during labor requiring blood transfusions. Fetal iron stores in the first 6 months of life are dependent upon maternal stores during pregnancy. Post-partum anemia is a contributing factor to postpartum depression.
Symptoms of iron deficiency anemia include:
• Easy fatigability
• Tachypnea on exertion
• Pica (craving for specific foods or nonfood items, e.g., ice chips, laundry starch, dirt)
• Muscle dysfunction
• Appetite loss
• Poor scholastic performance
• Altered resistance to infection
• Altered behavior
• Smooth tongue*
• Brittle nails*
• Cheilosis (fissures at the corners of the mouth)*
*In severe iron deficiency
Improving iron status noticeably and rapidly improves most of these symptoms.
Iron deficiency anemia is diagnosed on the basis of simple, inexpensive screening tests. Hematocrit (Hct) and hemoglobin (Hb), both of which can often be done in-office by an obstetrician or midwife, are the most commonly ascertained values. The mean cell volume (MCV) is done to assess red blood cell (RBC) size to rule out anemia caused by nutritional deficiencies other than iron, for example, vitamin B12 deficiency, which causes macrocytic anemia. Hematocrit is a measure of the percentage of whole blood occupied by red blood cells, the oxygen and iron-carrying portions of the blood, and hemoglobin is the concentration of iron-containing protein in the red blood cells. The normal hematocrit in nonpregnant women ranges from 36% to 45%. However, in pregnant women, because of normally increased blood volume (physiologic hemodilution of pregnancy), values can be as low as 34% in singleton and 30% in twin or multiple pregnancy, even with normal stores of iron stores, and does not necessarily indicate a true anemia. Normal hemoglobin for women ranges between 12 to 16 g / dL, with a drop down to 10.5 possibly normal in mid-pregnancy (weeks 16 to 28) owing to physiologic hemodilution. Diagnosis also may be made on the basis of an increase in hemoglobin levels after supplementation has begun. Additional tests, including serum ferritin concentration, and transferrin levels can also be used to differentiate iron deficiency anemia from other forms of anemia. This is usually only necessary during pregnancy when anemia is refractory to treatment.
Iron deficiency anemia can be a result of chronic internal bleeding that can occur, for example, in the case of gastrointestinal disease (e.g., inflammatory bowel disease, celiac disease, peptic ulcer disease). Causes of microcytic anemia that must be ruled out include thalassemia, anemia of chronic disease, sideroblastic anemia, and lead poisoning.
Conventional treatment of iron deficiency anemia relies primarily on diet and iron supplements.
Red meat, poultry, and fish are good sources of heme iron, the most absorbable form. Iron deficiency anemia is lowest in areas where red meat is a dietary staple. Dietary sources of non-heme iron include blackstrap molasses, dried apricots, raisins, dark green leafy vegetables (e.g., kale, collards), kidney beans, lentils, mussels, oysters, pine nuts, pumpkin seeds, quinoa, tempeh, tofu, and wheat germ. Non-heme sources of iron are also an important part of the diet, though not as readily absorbable. A carefully planned diet rich in a variety of iron sources can allow vegetarians to meet their dietary iron needs.
Oral iron supplements are an inexpensive, generally safe, and simple way to treat iron deficiency. Because iron is best absorbed from the duodenum and proximal jejunum, time released and enteric coated preparations are not very effective, and they are also much more costly. Ascorbic acid increases the absorbability of non-heme iron. Taking 250 mg of vitamin C with iron supplement is therefore advisable. Phytates, oxalates, carbonates, calcium, and tannins, found in foods such as cereals, dietary fiber, tea, coffee, eggs, and milk, interfere with iron absorption; therefore, iron supplements should not be taken with food. Antacids also interfere with iron absorption, and should be given several hours prior to or after taking iron supplements. Antibiotics also interfere with iron absorption. Gastrointestinal (GI) side effects are common (10% to 20% of patients report GI side effects) with conventional iron supplements (see Botanical Treatment of Iron Deficiency Anemia for herbal alternatives). Constipation is a common complaint, as are nausea, vomiting, abdominal discomfort, and diarrhea. Elemental iron in the forms of ferrous sulfate, ferrous fumarate, or ferrous gluconate may be substituted with ferrous sulfate elixir, a liquid preparation that may cause fewer GI symptoms. Improvement can usually be observed starting approximately 7 days after the onset of iron supplementation. Also, though a less effective therapy, iron supplements may be taken with meals to avoid discomfort. The various forms of iron commonly used therapeutically appear to be equally effective. In severe cases where oral iron is unable to be tolerated, parenteral iron may be given. It is considered optimal to remain on iron supplements for approximately 6 months after iron levels return to normal in order to adequately replenish depleted iron stores. Low-dose iron supplementation (30 mg / day) throughout pregnancy is as effective as higher dose supplementation (e.g., 60 mg day) and less likely to cause side effects. If a patient does not respond to iron therapy, the possibility of an underlying disorder or coexisting disease (e.g., GI bleeding, thalassemia, and so forth.) must be addressed. Malabsorption is also a common problem leading to refractory anemia.
Iron Deficiency: Case History
Celeste is a 28-year-old woman who is 29 weeks pregnant with her second baby. She has a history of iron deficiency anemia for which she has been under the care of her obstetrician. In spite of 6 weeks of treatment, her hematocrit, which is 29, has not increased. Her physician doubled her iron supplement to 60 mg / day, and she is now experiencing side effects, including severe constipation for 2 weeks, nausea, and abdominal cramps. Her skin color has a slightly greenish tint around her mouth and under her eyes. She is deeply fatigued and has a poor appetite, as well as daily headaches. Recommendations:
• Discontinue taking the prescription iron supplement.
• Take Floradix Iron and Herbs as instructed on the bottle.
After 1 week, Celeste was still constipated, so she was instructed to add the following to her plan: For constipation:
• Take Yellow-Dock Dandelion Root Syrup (1 tbl each morning)
• Soak 4 dried prunes and 1 tablespoon bran per ¼ cup warm, unfiltered apple juice until prunes are soft. Eat / drink entire portion once each morning for constipation.
Three weeks after the initial visit (31 weeks pregnant), Celeste’s hematocrit had risen to 30, and she was having regular bowel movements — one soft, formed stool per day or every other day. It was recommended that she continue taking the preparations for constipation each morning for a couple of additional weeks. It was also recommended that she add 1 tbl liquid chlorophyll to her protocol daily, and take 250 mg vitamin C with each dose of Floradix. It was felt somewhat urgent to quickly raise her hematocrit, as her due date was only 9 weeks away.
At 34 weeks pregnancy, Celeste’s hematocrit was 32, and now that her bowels were regular, she was instructed to start eating beef stew three times per week (organic beef). At 36 weeks, Celeste’s hematocrit was 34, and by 37 weeks it had risen to 35. Celeste gave birth at home, with the midwife who had assisted her in treating her anemia, at 38 weeks, to a healthy baby boy.