Our digestion does not really screen excess iron, and our elimination is low after we absorb it. Therefore, it is fairly easy to get iron overloads in the body, although it is much easier to develop an iron deficiency.
Those most vulnerable to iron deficiency are infants, adolescents, pregnant or lactating women, vegetarians, people on diets, premenopausal women, and people with bleeding problems. People taking certain drugs, such as allopurinol for gout, tetracyclines, or high amounts of aspirin, may have impaired absorption of iron and thus may develop iron deficiency over time.
Both iron deficiency anemia and iron deficiency without anemia occur fairly commonly when a rapid growth period increases iron needs which are often not met with additional dietary intake. Several studies have shown that often more than half of children aged 1-5, teenagers, and women aged 18-44 had iron intakes below the RDA.
Females need more iron than men but often consume less. Iron deficiency is particularly common in pregnancy, especially later pregnancy, when the fetus needs about 7-8 mg. per day. Even though there is better absorption at this time than the average 10-20 percent of intake, the average diet supplies only 15-25 mg. per day, which is not enough to meet the needs of both mother and child.
Iron deficiency anemia is characterized as microcytic (the RBCs are small) and hypochromic (the RBCs are pale because of decreased hemoglobin). This type of anemia can be determined by doing a complete blood count and checking the hemoglobin, hematocrit, and red blood cell count, along with the RBC indices-the MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin), and MCHC (mean corpuscular hemoglobin concentration). The doctor or lab technician can also easily see small, pale red blood cells under the microscope. Iron deficiency can occur and generate vague symptoms before clinical anemia actually occurs. This state may be assessed by checking the serum iron concentration. If this is low, it may suggest iron deficiency, usually from low intake or increased losses. Even before serum iron is low, iron saturation, serum transferrin (iron-carrying protein), total iron binding capacity (TIBC), or, more recently, the ferritin level may be measured to detect low iron stores. The body will draw on these muscle and tissue stores to maintain normal serum levels.
Anemia is basically defined as a reduction in the number of red blood cells. Other factors besides iron, such as low copper, manganese, zinc, pyridoxine (vitamin B6), folic acid, and vitamin B12 may also affect the RBCs. Vitamin B6 and zinc deficiency may mimic iron deficiency, but giving iron may lead to iron toxicity problems in these cases. Measuring serum iron is the best way to ensure that the problem is actually iron deficiency, and measuring B6 and zinc levels can help diagnose those hidden, though common, deficiency problems as well. So iron deficiency is but one cause of anemia. I have discussed the B12 and folic acid vitamin deficiency anemias in Chapter 5, Vitamins; copper, zinc, and manganese are some minerals whose deficiency can cause other forms of anemia. Thyroid problems or lead toxicity may cause anemia as well. We also need adequate protein, calcium, and vitamins E and C to keep our red blood cells healthy. Thus, many nutritionally related problems can lead to anemia; decreased production or increased destruction of RBCs and bleeding, however, are the most common causes. Overall, it is wise to diagnose and treat the definitive cause of anemia, not just give iron.
Many symptoms may arise from iron deficiency. Fatigue and lack of stamina usually arise first, caused by fewer red blood cells, low hemoglobin, and a reduced ability to hold and carry oxygen. Children who are iron deficient may experience psychological problems, learning disabilities based on hyperactivity or a decreased attention span, and even a lower IQ, besides other symptoms of anemia. Headaches, dizziness, weight loss from decreased appetite, constipation, and lowered immunity (a weakened resistance) may occur. With anemia, paleness of the skin, cheeks, lips, and tongue may occur, as can a sore tongue, canker sores in the mouth, hair loss, itching, and brittle nails. Not uncommon is a general state of apathy, irritability, and/or depression—a lack of enthusiasm for life—which can, however, improve rapidly with iron supplementation. Decreased memory may also occur. In children particularly, iron deficiency may cause a strange symptom called "pica"—eating and sucking on inedible objects, such as toys, clay, or ice. This usually disappears with iron treatment. In pregnancy, morning sickness may occur more frequently with low iron, perhaps because of the relatively low oxygen distribution to cells. It can take several months for improved absorption and increased intake to catch up to needs.
RDAs for Iron
|0-6 months||10 mg.|
|6 months-1 year||15 mg.|
|1-3 years||15 mg.|
|4-6 years||10 mg.|
|7-10 years||10 mg.|
|11-18 years||18 mg.|
|19 years and older||10 mg.|
|11-50 years (during years of menstruation)||18 mg.|
|51 years and older (or non-menstrual years)||10 mg.|
|Pregnant women||45–60 mg.|
|Lactating women||45–60 mg.|
In general, it is wise to discover the cause of iron deficiency. Is it from low intake? If so, the diet should be evaluated. Or is it due to poor absorption? Then check the absorption factors such as low stomach acid. Or is there some bleeding problem, especially a slow blood loss? Intestinal bleeding, as in colitis, ulcers, or even hemorrhoids, is not uncommon. Excess menstrual bleeding, often with the presence of uterine fibroids, is a common cause of iron loss in women. Parasites can cause iron deficiency anemia, as can cancer. Donating blood too frequently can lead to anemia and iron deficiency symptoms. Supplementing iron may help over time, but it is especially important to rule out any internal bleeding.
Requirements: The RDA for adult men and postmenopausal women is 10 mg. per day; for teenagers and women of childbearing age, it is 18 mg. per day. This is based on an average absorption of 10 percent to replace daily losses and to maintain iron storage levels of about 500 mg.
Iron needs increase with growth and development, when more red blood cells and body tissues are being made; during pregnancy, when extra iron is going to the growing fetus; and for at least several months postpartum during lactation, when losses through milk are high. But the average daily intake is only about 6 mg. per 1,000 calories consumed, so a 2,000-calorie diet supplies only 12 mg., which is less than is needed by most teenagers and women, especially during pregnancy and lactation. Luckily, when body needs increase, iron absorption improves, and we usually develop a craving or taste for iron-containing foods as part of our natural survival and health instincts.
Most people, especially women, should be aware of iron intake and absorption. Eating vitamin C-containing foods along with the high-iron foods or taking an ascorbic acid supplement, even 50–100 mg., improves the absorption of iron in supplements. Protein foods improve absorption and usually have a higher iron content, so eating more of these foods, such as meats and legumes, as well as leafy greens, helps get more iron into the body.
Iron supplements are strongly recommended when there are increased requirements, as with teenagers and most women, especially with heavy or long menstrual flow and definitely during pregnancy and lactation, when iron needs may triple. Most men, however, unless there is some bleeding problem, do not require additional iron. When there is sufficient iron intake, more will not necessarily help; in fact, it could lead to problems associated with excess iron storage over a period of time.
The ferrous (2+) forms of iron, not the ferric (3+) state, are the forms to have in supplements. Ferrous sulfate is the most commonly prescribed form of iron, although ferrous fumarate and gluconate are also prescribed by doctors. As an example, 325 mg. (5 grains) of ferrous sulfate contains about 120 mg. of elemental iron. With at least a 10 percent absorption rate, that allows more than 12 mg. of iron per tablet to get into the body; if these are taken several times daily in pregnancy or in anemia, as some doctors recommend, this may be excessive.
To improve iron absorption, take the iron with 250 mg. of vitamin C and between meals, if tolerated. During pregnancy, the increased need will also improve the percentage absorbed. Ferrous sulfate is often used because it is inexpensive and fairly assimilable for most women, though it can also be irritating to the gastrointestinal tract and cause constipation or blackening of the stools, which could cover up an intestinal bleeding problem (blood in the stool can also cause it to be black). Ferrous gluconate and fumarate are considered organic irons (as found in living tissues) and are also inexpensive and have good absorption, and they tend to cause fewer symptoms (constipation, intestinal upset) than the inorganic ferrous sulfate. The dosages are similar; 325 mg. of ferrous gluconate taken two or three times daily during pregnancy or to treat iron deficiency or blood losses. These amounts should not be taken regularly as a preventive or safeguard.
The form that probably is best assimilated and easiest on the intestinal tract is the hydrolyzed protein chelate of iron—that is, "chelated" iron. Usually about 50 mg. of chelated elemental iron taken once or twice daily will satisfy most iron needs during pregnancy or with iron deficiency. This can be used until the iron and red blood cell levels are normalized. The choice of form for iron supplements is based on absorption and gentleness. In order of preference, the suggested forms are chelated iron, such as iron aspartate, ferrous succinate, and ferrous fumarate, followed by ferrous gluconate and ferrous lactate. Ferrous sulfate is commonly used but produces more symptoms than the other forms.
There is some concern about vitamin E's interaction with iron. It can bind the iron to a nonutilizable form, which then can oxidize and thus inactivate the vitamin E when the two are taken together, though this occurs more so with the ferric forms of iron. Ferrous sulfate has some interaction with E. The organic forms of iron—gluconate, aspartate, and fumarate—as well as the chelated iron have little effect on reducing vitamin E. But, to be safe, it is best not to take vitamin E with iron but to take it by itself at night or in the morning.
Overall, iron is a very important mineral of which we must be constantly aware. Extra iron is not needed by everyone, but when it is required, we must increase iron foods or take supplemental iron to prevent loss of energy and enthusiasm for life and the many other problems caused by iron deficiency.