IRON

 

Iron is part of hemoglobin, the oxygen-carrying component of the blood. Iron-deficient people tire easily in part because their bodies are starved for oxygen. Iron is also part of myoglobin, which helps muscle cells store oxygen. Without enough iron, ATP (the fuel the body runs on) cannot be properly synthesized. As a result, some iron-deficient people become fatigued even when their hemoglobin levels are normal (i.e., when they are not anemic).

Anemia is a reduction in the number of red blood cells (RBCs); in the amount of hemoglobin in the blood (hemoglobin is the iron-containing pigment of the red blood cells that carries oxygen from the lungs to the tissues); and in another related index called hematocrit (the volume of RBCs after they have been spun in a centrifuge). All three values are measured on a complete blood count, which doctors shorten to “CBC.” Iron-deficiency anemia is unique and can be distinguished from other forms of anemia by the fact that it causes RBCs to be abnormally small and pale, an observation easily appreciated by viewing a blood sample through a microscope.

To rule out an iron deficiency in the absence of anemia, a doctor needs to run one or several of a group of special lab tests (such as serum ferritin, which measures the body’s iron stores). People should never be told their body has sufficient iron simply because they are not anemic.

Iron deficiency, whether it is severe enough to lead to anemia or not, can have many non-nutritional causes (such as excessive menstrual bleeding, bleeding ulcers, hemorrhoids, gastrointestinal bleeding caused by aspirin or related drugs, frequent blood donations, or colon cancer) or can be caused by a lack of dietary iron. Menstrual bleeding is probably the leading cause of iron deficiency. However, despite common beliefs to the contrary, only about one premenopausal women in ten is iron deficient.1 Deficiency of vitamin B12, folic acid, vitamin B6, or copper can cause other forms of anemia; many forms of non-nutritional anemia exist, but this article will only cover iron-deficiency anemia.

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Although iron is part of the antioxidant enzyme catalase, iron is not generally considered an antioxidant, because too much iron can cause oxidative damage.


 

Checklist for Iron-Deficiency Anemia

Rating Nutritional Supplements Herbs
3Stars Iron
Liver extracts		  
2Stars Vitamin A (as an adjunct to supplemental iron)
Vitamin C (as an adjunct to supplemental iron)		  
1Star Betaine HCl (as an adjunct to supplemental iron)  
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

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What are the symptoms of iron-deficiency anemia? Some common symptoms of anemia include fatigue, lethargy, weakness, poor concentration, and impaired immune function. In iron-deficiency, fatigue also occurs because iron is needed to make optimal amounts of ATP—the energy source the body runs on. This fatigue usually begins long before a person is anemic. Said another way, a lack of anemia does not rule out iron deficiency in tired people. Another symptom of anemia, called pica, is the desire to eat unusual things, such as ice, clay, cardboard, paint, or starch. Advanced anemia may also result in lightheadedness, headaches, ringing in the ears (tinnitus), irritability, pale skin, unpleasant sensations in the legs with an uncontrollable urge to move them (restless legs syndrome), and getting winded easily.

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How is it treated? Conventional therapy involves a combination of treating the underlying causes of iron deficiency and replacing iron. Common forms of iron include ferrous sulfate (Feosol®, Fer-In-Sol®, Mol-Iron®, Slow Fe®), ferrous fumarate (Femiron®, Feostat®, Fumerin®, Hemocyte®, Ircon®), ferrous gluconate (Fergon®, Ferralet®, Simron®), and polysaccharide-iron complex (Niferex®, Nu-Iron®). Common side effects of iron pills include constipation, diarrhea, nausea, and vomiting. Iron may be administered intravenously for those who cannot tolerate the oral forms.

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Dietary changes that may be helpful: Iron deficiency is not usually caused by a lack of dietary iron alone. Nonetheless, a lack of iron in the diet is often part of the problem, so ensuring an adequate supply of iron is important for people with a documented deficiency. The most absorbable form of iron, called “heme” iron, is found in meat, poultry, and fish. Non-heme iron is also found in these foods, as well as in dried fruit, molasses, leafy green vegetables, wine, and most iron supplements. Acidic foods (such as tomato sauce) cooked in an iron pan can leech iron into the food and thus also be a source of dietary iron.

Vegetarians eat less iron than non-vegetarians, and the iron they eat is somewhat less absorbable. As a result, vegetarians are more likely to have reduced iron stores.2 Vegetarians can increase their iron intake by emphasizing iron-containing foods within their diet (see above), or in some cases by supplementing iron, if needed.

Coffee interferes with the absorption of iron.3 However, moderate intake of coffee (4 cups per day) may not adversely affect risk of iron-deficiency anemia when the diet contains adequate amounts of iron and vitamin C.4 Black tea contains tannins that strongly inhibit the absorption of non-heme iron. In fact, this iron-blocking effect is so effective that drinking black tea can help treat hemochromatosis, a disease of iron overload.5 Consequently, people who are iron deficient should avoid drinking tea.

Fiber is another dietary component that can reduce the absorption of iron from foods. Foods high in bran fiber can reduce the absorption of iron from foods consumed at the same meal by half.6 Therefore, it makes sense for people needing to take iron supplements to avoid doing so at mealtime if the meal contains significant amounts of fiber.

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Nutritional supplements that may be helpful: Before iron deficiency can be treated, it must be diagnosed and the cause must be found by a doctor. In addition to addressing the cause (e.g., avoiding aspirin, treating a bleeding ulcer, etc.), supplementation with iron is the primary way to resolve iron-deficiency anemia.

If a doctor diagnoses iron deficiency, iron supplementation is essential. Though some doctors use higher amounts, a common daily dose for adults is 100 mg per day. Even though symptoms of deficiency should disappear much sooner, iron deficient people usually need to keep supplementing with iron for six months to one year until the ferritin test is completely normal. Even after taking enough iron to overcome the deficiency, some people with recurrent iron deficiency—particularly some premenopausal women—need to continue to supplement with smaller levels of iron, such as the 18 mg present in most multivitamin-mineral supplements. This need for continual iron supplementation even after deficiency has been overcome should be determined by a doctor.

Liver extracts from beef are a rich natural source of many vitamins and minerals, including iron. Bovine liver extracts provide the most absorbable form of iron—heme iron—as well as other nutrients critical in building blood, including vitamin B12 and folic acid. Liver extracts can contain as much as 3–4 mg of heme iron per gram.

Taking vitamin A and iron together has been reported to help overcome iron deficiency more effectively than iron supplements alone.7 Although the optimal amount of vitamin A needed to help people with iron deficiency has yet to be established, some doctors recommend 10,000 IU per day.

Vitamin C increases the absorption of non-heme iron.8 Some doctors advise iron-deficient people to take vitamin C (typically 100–500 mg) at the same time as their iron supplement.9

Hydrochloric acid produced by the stomach improves the absorption of non-heme iron from food and supplements. 10 11 Some practitioners recommend a hydrochloric acid supplement, e.g., betaine hydrochloride (betaine HCl), to enhance iron absorption in people with iron-deficiency anemia.

A high degree of association between iron-deficiency anemia and vitamin D deficiency in Asian children has been previously reported.12 In three different ethnic groups living in England, iron-deficiency anemia was found to be a significant risk factor for low vitamin D levels in children.13 These findings suggest that children with iron-deficiency anemia should be screened for vitamin D deficiency and be given vitamin D supplements if necessary.

Where is it found? The most absorbable form of iron, called “heme” iron, is found in oysters, meat and poultry, and fish. Non-heme iron is also found in these foods, as well as in dried fruit, molasses, leafy green vegetables, wine, and iron supplements. Acidic foods (such as tomato sauce) cooked in an iron pan can also be a source of dietary iron.

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Iron has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
3Stars Athletic performance (for treatment of iron-deficiency only)
Childhood intelligence (for deficiency)
Depression (for deficiency)
Iron-deficiency anemia
Menorrhagia (heavy menstruation) (for treatment of iron- deficiency only)
2Stars Breast-feeding support
Canker sores
Celiac disease (for treatment of iron-deficiency only)
Pre- and post-surgery health (if deficient or for major surgery)
Pregnancy and Postpartum support (with medical supervision)
Restless legs syndrome (only if iron- deficiency)
1Star Alzheimer’s disease (in combination with coenzyme Q10 and vitamin B6)
Dermatitis Herpetiformis
HIV support
Infertility (female) (for treatment of iron- deficiency only)
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

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Who is likely to be deficient? Vegetarians eat less iron than non-vegetarians, and the iron they eat is somewhat less absorbable. As a result, vegetarians are more likely to have reduced iron stores.1 However, iron deficiency is not usually caused by a lack of iron in the diet alone. An underlying cause, such as iron loss in menstrual blood, often exists.

Pregnant women, marathon runners, people who take aspirin, and those who have parasitic infections, hemorrhoids, ulcers, ulcerative colitis, Crohn’s disease, gastrointestinal cancers, or other conditions that cause blood loss or malabsorption are likely to become deficient.

Infants living in inner city areas may be at increased risk of iron-deficiency anemia 2 and suffer more often from developmental delays as a result.3 4 Supplementation of infant formula with iron up to 18 months of age in inner city infants has been shown to prevent iron-deficiency anemia and to reduce the decline in mental development seen in such infants in some,5 but not all,6 studies.

Breath-holding spells are a common problem affecting about 27% of healthy children.7 These spells have been associated with iron-deficiency anemia,8 and several studies have reported improvement of breath-holding spells with iron supplementation.9 10 11 12

People who fit into one of these groups, even pregnant women, shouldn’t automatically take iron supplements. Fatigue, the first symptom of iron deficiency, can be caused by many other things. A doctor should assess the need for iron supplements, since taking iron when it isn’t needed does no good and may do some harm.

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Which forms of supplemental iron are best? All iron supplements are not the same. Ferrous iron (e.g. ferrous sulfate) is much better absorbed than ferric iron (e.g. ferric citrate).13 14 The most common form of iron supplement is ferrous sulfate, but it is known to produce intestinal side effects (such as constipation, nausea, and bloating) in many users.15 Some forms of ferrous sulfate are enteric-coated to delay tablet dissolving and prevent some side effects,16 but enteric-coated iron may not absorb as well as iron from standard supplements.17 18 19 Other forms of iron supplements, such as ferrous fumarate,20 21 ferrous gluconate,22 heme iron concentrate,23 24 25 26 and iron glycine amino acid chelate27 28 are readily absorbed and less likely to cause intestinal side effects.

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How much is usually taken? If a doctor diagnoses iron deficiency, iron supplementation is essential. To treat iron deficiency, a common recommended amount for an adult is 100 mg per day; that amount is usually reduced after the deficiency is corrected. When iron deficiency is diagnosed, the doctor must also determine the cause. Usually it’s not serious (such as normal menstrual blood loss or blood donation). Occasionally, however, iron deficiency signals ulcers or even colon cancer.

Some premenopausal women become marginally iron deficient unless they supplement with iron. However, the 18 mg of iron present in many multivitamin-mineral supplements is often adequate to prevent deficiency. A doctor should be consulted to determine the amount of iron that is needed.

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Are there any side effects or interactions? Iron (ferrous sulfate) is the leading cause of accidental poisonings in children.29 30 31 The incidence of iron poisonings in young children increased dramatically in 1986. Many of these children obtained the iron from a child-resistant container opened by themselves or another child, or left open or improperly closed by an adult.32 Deaths in children have occurred from ingesting as little as 200 mg to as much as 5.85 grams of iron.33 Keep iron-containing supplements out of a child’s reach.

Hemochromatosis, hemosiderosis, polycythemia, and iron-loading anemias (such as thalassemia and sickle cell anemia) are conditions involving excessive storage of iron. Supplementing iron can be quite dangerous for people with these diseases.

Supplemental amounts required to overcome iron deficiency can cause constipation. Sometimes switching the form of iron (see “Which forms of supplemental iron are best?” above), getting more exercise, or treating the constipation with fiber and fluids is helpful, though fiber can reduce iron absorption (see below). Sometimes the amount of iron must be reduced if constipation occurs.

Some researchers have linked excess iron levels to diabetes,34 cancer,35 increased risk of infection,36 systemic lupus erythematosus (SLE),37 exacerbation of rheumatoid arthritis,38 and Huntington’s disease.39 The greatest concern has surrounded the possibility that excess storage of iron in the body increases the risk of heart disease.40 41 42 Two analyses of published studies came to different conclusions about whether iron could increase heart disease risk.43 44 One trial has suggested that such a link may exist, but only in some people (possibly smokers or those with elevated cholesterol levels).45 The link between excess iron and any of the diseases mentioned earlier in this paragraph has not been definitively proven. Nonetheless, too much iron causes free radical damage, which can, in theory, promote or exacerbate most of these diseases. People who are not iron deficient should generally not take iron supplements.

Patients on kidney dialysis who are given injections of iron frequently experience “oxidative stress”. This is because iron is a pro-oxidant, meaning that it interacts with oxygen molecules in ways that can damage tissues. These adverse effects of iron therapy may be counteracted by supplementation with vitamin E.46

Supplementation with iron, or iron and zinc, has been found to improve vitamin A status among children at high risk for deficiency of the three nutrients. 47

People with hepatitis C who have failed to respond to interferon therapy have been found to have higher amounts of iron within the liver. Moreover, reduction of iron levels by drawing blood has been shown to decrease liver injury caused by hepatitis C.48 Therefore, people with hepatitis C should avoid iron supplements.

In some people, particularly those with diabetes, insulin resistance syndrome, or liver disease, a genetic susceptibility to iron overload has been reported.49

Many foods, beverages and supplements have been shown to affect the absorption of iron.50

Foods, beverages and supplements that interfere with iron absorption include:

Foods and supplements that increase iron absorption include:

Although vitamin C increases iron absorption,76 77 78 79 the effect is relatively minor.80

Taking vitamin A with iron helps treat iron deficiency, since vitamin A improves the absorption and/or utilization of iron.81 82

Although soy protein has been shown to decrease iron absorption (see above), certain soy-containing foods (e.g. tofu, miso, tempeh) have significantly improved iron absorption.83 Some soy sauces may also enhance iron absorption.84

Alcohol, but not red wine, has been reported to increase the absorption of ferric, but not ferrous, iron.85 86

Iron has been reported to potentially interfere with manganese absorption. In one trial, women with high iron status had relatively poor absorption of manganese.87 In another trial studying manganese/iron interactions in women, increased intake of “non-heme iron”—the kind of iron found in most supplements—decreased manganese status.88 These interactions suggest that taking multiminerals that include manganese may protect against manganese deficiencies that might otherwise be triggered by taking isolated iron supplements.

Are there any drug interactions? Certain medications may interact with iron. Refer to the drug interactions safety check for a list of those medications.

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