Iron

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What other names is Iron known by?

Atomic Number 26, Carbonate de Fer Anhydre, Citrate de Fer, Elemental Iron, Fe, Fer, Fer Élémentaire, Ferric Iron, Ferric Orthophosphate, Ferrous Carbonate Anhydrous, Ferrous Citrate, Ferrous Fumarate, Ferrous Gluconate, Ferrous Iron, Ferrous Pyrophosphate, Ferrous Sulfate, Ferrum Phosphoricum, Fumarate de Fer, Gluconate de Fer, Glycérophosphate de Fer, Heme Iron Polypeptide, Hierro, Iron Glycerophosphate, Orthophosphate de Fer, Orthophosphate Ferrique, Numéro Atomique 26, Polypeptide de Fer de Heme, Pyrophosphate de Fer, Sulfate de Fer.

What is Iron?

Iron is a mineral. Most of the iron in the body is found in the hemoglobin of red blood cells and in the myoglobin of muscle cells. Iron is needed for transporting oxygen and carbon dioxide. It also has other important roles in the body.

People take iron supplements for preventing and treating low levels of iron (iron deficiency) and the resulting iron deficiency anemia. In people with iron deficiency anemia, the red blood cells can't carry enough oxygen to the body because they don't have enough iron. People with this condition often feel very tired.

Iron is also used for improving athletic performance and learning problems, and treating attention deficit-hyperactivity disorder (ADHD), restless legs syndrome (RLS), and canker sores. Some people also use iron for Crohn's disease, heart failure, breath-holding attacks in children, growth in children, depression, fatigue, improving thinking, and the inability to get pregnant.

Women sometimes take iron supplements to make up for iron lost in heavy menstrual periods. Iron-rich foods, such as pork, ham, chicken, fish, beans, and especially beef, liver, and lamb are also used.

Effective for...

  • Anemia caused by chronic disease. Many diseases such as cancer, kidney problems, or heart problems can cause anemia. Taking iron along with other medications such as epoetin alfa can help build red blood cells and reverse anemia in people with kidney problems or being treated for cancer with chemotherapy. Receiving iron intravenously is more effective than taking supplements by mouth.
  • Iron deficiency. Taking iron supplements is effective for treating and preventing iron deficiency and anemia caused by too little iron in the body.
  • Iron deficiency during pregnancy. Taking iron might reduce the risk of anemia caused by too little iron in the body when taken by women who are pregnant.

Possibly Effective for...

  • Coughs caused by ACE inhibitors. Medications used for high blood pressure called ACE inhibitors can sometimes cause coughing as a side effect. Some research shows that taking an iron supplement might reduce or prevent this side effect. The ACE inhibitor medications include captopril (Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and many others.
  • Improving thinking. Taking iron might help improve thinking, learning, and memory in children with low levels of iron. An early study suggests that taking iron might improve attention in adolescent girls with unknown iron status.
  • Heart failure. Up to 20% of people who have heart failure also have low levels of iron in the body. Some research shows that giving iron intravenously can improve symptoms of heart failure. It is not yet known if taking an iron supplement by mouth would help.
  • Restless legs syndrome (RLS). Research shows that taking iron by mouth decreases symptoms of RLS such as leg discomfort and sleep problems. In fact, taking iron to improve symptoms is recommended for people with RLS and low iron levels. Some people with RLS also have improved symptoms after having iron injected into the vein (by IV). But it's too soon to know if all forms of iron work when given by IV.

Insufficient Evidence to Rate Effectiveness for...

  • Attention deficit-hyperactivity disorder (ADHD). Developing research shows that taking iron sulfate (an iron-containing chemical compound) improves some measures of attention deficit-hyperactivity disorder (ADHD) in children with iron deficiency after 1-3 months of treatment.
  • Breath-holding attacks. Early research suggests that taking iron by mouth or through a shot reduces the frequency of breath-holding attacks in children.
  • Child development. Early research shows that iron does not improve mental performance in infants and children who do not have anemia. However, there might be an improvement in the development of motor skills such as coordination. Other early evidence suggests that taking iron supplements alone by mouth does not increase growth in children.
  • Fatigue. There is some early evidence that a specific iron supplement (Tardyferon) might improve unexplained fatigue in non-anemic women.
  • Physical performance. Research shows that iron supplementation can improve the ability to exercise in younger women. Additional early research suggests that iron can improve physical performance in children.
  • Canker sores.
  • A digestive tract disease called Crohn's disease.
  • Depression.
  • Female infertility.
  • Heavy menstrual bleeding.
  • Other conditions.
More evidence is needed to rate iron for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

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How does Iron work?

Iron helps red blood cells deliver oxygen from the lungs to cells all over the body. Once the oxygen is delivered, iron then helps red blood cells carry carbon dioxide waste back to the lungs to be exhaled. Iron also plays a role in many important chemical reactions in the body.

Are there safety concerns?

Iron is LIKELY SAFE for most people when it is taken by mouth or injected into the vein in appropriate amounts. However, it can cause side effects including stomach upset and pain, constipation or diarrhea, nausea, and vomiting. Taking iron supplements with food seems to reduce some of these side effects. However, food can also reduce how well the body absorbed iron. Iron should be taken on an empty stomach if possible. If it causes too many side effects, it can be taken with food. Try to avoid taking it with foods containing dairy products, coffee, tea, or cereals.

There are many forms of iron products such as ferrous sulfate, ferrous gluconate, ferrous fumarate, and others. Some products, such as those containing polysaccharide-iron complex (Niferex-150, etc), claim to cause fewer side effects than others. But there is no reliable evidence to support this claim.

Some enteric coated or controlled release iron products might reduce nausea for some people; however, these products also have less absorption by the body.

Liquid iron supplements may blacken teeth.

High doses of iron are LIKELY UNSAFE, especially for children. Iron is the most common cause of poisoning deaths in children. Doses as low as 60 mg/kg can be fatal. Iron poisoning can cause many serious problems including stomach and intestinal distress, liver failure, dangerously low blood pressure, and death. If you suspect an adult or child has taken more than the recommended amount of iron, call your healthcare professional or the nearest poison control center immediately.

There is some concern that high intake of iron might increase the chance of developing heart disease. Some studies show that people with high intake of iron, especially from food sources such as red meat, are more likely to have heart disease. This may be especially true for people with type 2 diabetes. But this is controversial. Other studies do not show that iron increases the chance of heart disease. It is too soon to tell for sure if iron increases the chance of heart disease.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Iron is LIKELY SAFE for pregnant and breast-feeding women who have enough iron stored in their bodies when used in doses below the tolerable upper intake level (UL) of 45 mg per day of elemental iron. The UL is the highest level of intake at which no harmful side effects are expected. However, iron is LIKELY UNSAFE when taken by mouth in high doses. If you do not have iron deficiency, do not take more than 45 mg per day of elemental iron per day. Higher doses frequently cause stomach and intestinal side effects such as nausea and vomiting. High levels of hemoglobin at the time of delivery are associated with bad pregnancy outcomes. Hemoglobin is the molecule in red blood cells that contains iron.

Diabetes: There is concern that a diet that is high in iron might increase the risk of heart disease in women with type 2 diabetes, although this has not been proven. If you have diabetes, discuss your iron intake with your healthcare provider.

Stomach or intestinal ulcers: Iron might cause irritation and make these conditions worse. Use iron with care.

Intestinal inflammation, such as ulcerative colitis or Crohn's disease: Iron might cause irritation and make these conditions worse. Use iron with care.

Hemoglobin disease, such as thalassemia: Taking iron might cause iron overload in people with these conditions. If you have a hemoglobin disease, don't take iron unless directed to do so by your healthcare provider.

Premature infants: Giving iron to premature infants with low blood levels of vitamin E can cause serious problems. The vitamin E deficiency should be corrected before giving iron. Talk with your healthcare provider before giving iron to a premature infant.

Are there any interactions with medications?



Antibiotics (Quinolone antibiotics)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Iron might decrease how much antibiotic the body absorbs. Taking iron along with some antibiotics might decrease the effectiveness of these antibiotics. To avoid this interaction take iron two hours before or two hours after taking antibiotics.

Some of these antibiotics that might interact with iron include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).



Antibiotics (Tetracycline antibiotics)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Iron can attach to tetracycline antibiotics in the stomach and decrease how much tetracycline antibiotics the body can absorb. Taking iron along with tetracycline antibiotics might decrease the effectiveness of tetracycline antibiotics. To avoid this interaction take iron two hours before or four hours after taking tetracyclines.

Some tetracycline antibiotics include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).



Bisphosphonates
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Iron can decrease how much bisphosphonate the body absorbs. Taking iron along with bisphosphonate can decrease the effectiveness of bisphosphonate. To avoid this interaction take bisphosphonate at least two hours before iron or later in the day.

Some bisphosphonates include alendronate (Fosamax), etidronate (Didronel), risedronate (Actonel), tiludronate (Skelid), and others.



Dolutegravir (Tivicay)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Dolutegravir (Tivicay) is a drug used for HIV infection. Iron can reduce how much dolutegravir the body absorbs. To avoid this interaction, take dolutegravir at least 2 hours before or 6 hours after taking iron.



Drugs used for HIV (Integrase inhibitors)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Taking iron along with integrase inhibitors might decrease blood levels of these drugs. This might decrease their effectiveness. Talk to your healthcare provider if you are using integrase inhibitors and want to start taking iron. Integrase inhibitors include dolutegravir (Tivicay), elvitegravir (Vitekta), and raltegravir (Isentress).



Levodopa
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Iron might decrease how much levodopa the body absorbs. Taking iron along with levodopa might decrease the effectiveness of levodopa. Do not take iron and levodopa at the same time.



Levothyroxine
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Levothyroxine is used for low thyroid function. Iron can decrease how much levothyroxine the body absorbs. Taking iron along with levothyroxine might decrease the effectiveness of levothyroxine.

Some brands that contain levothyroxine include Armour Thyroid, Eltroxin, Estre, Euthyrox, Levo-T, Levothroid, Levoxyl, Synthroid, Unithroid, and others.



Methyldopa (Aldomet)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Iron can decrease how much methyldopa (Aldomet) the body absorbs. Taking iron along with methyldopa (Aldomet) might decrease the effectiveness of methyldopa (Aldomet). To prevent this interaction take iron at least two hours before or after taking methyldopa (Aldomet).



Mycophenolate mofetil (CellCept)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

It is unclear how iron supplements might affect the body's absorption of mycophenolate mofetil. It has been suggested that iron might decrease how much mycophenolate mofetil (CellCept) the body absorbs. Therefore, taking iron along with mycophenolate mofetil (CellCept) might decrease the effectiveness of mycophenolate mofetil (CellCept). However, not all research has found that iron affects the body's absorption of mycophenolate. Therefore, it is not clear if this potential interaction is a serious concern. Until more is known, you should take iron at least four to six hours before, or two hours after taking mycophenolate mofetil (CellCept).



Penicillamine (Cuprimine, Depen)
Interaction Rating: Moderate Be cautious with this combination.
Talk with your health provider.

Penicillamine is used for Wilson's disease and rheumatoid arthritis. Iron might decrease how much penicillamine your body absorbs and decrease the effectiveness of penicillamine. To avoid this interaction take iron two hours before or two hours after taking penicillamine.



Chloramphenicol
Interaction Rating: Minor Be cautious with this combination.
Talk with your health provider.

Iron is important for producing new blood cells. Chloramphenicol might decrease new blood cells. Taking chloramphenicol for a long time might decrease the effects of iron on new blood cells. But most people only take chloramphenicol for a short time so this interaction isn't a big problem.

Dosing considerations for Iron.

The following doses have been studied in scientific research:

BY MOUTH:
  • Iron-deficiency in adults: 50-100 mg elemental iron three times daily. Doses between 30-120 mg weekly have been used in adult women. For treating children with iron deficiency anemia: the dose is 4-6 mg/kg per day divided into three doses. For both adults and children, 2-3 months of treatment can reverse anemia but might not rebuild the body's supply of stored iron. Therefore, treatment is usually continued another 6 months to build up the body's iron reserves.
  • For preventing iron deficiency in children, the American Academy of Pediatrics recommends iron supplements for some groups. For breast-fed infants, elemental iron 1 mg/kg/day is recommended from ages 4-6 months. Infants from 6-12 months should get 11 mg/day from food or supplements. For pre-term infants, 2 mg/kg/day for the first year is recommended. This should be continued until the baby is switched to formula or otherwise getting enough iron from food sources. Formula-fed children get enough iron from infant formula. Toddlers aged 1-3 years usually get enough iron from foods to meet the recommended daily amount of 7 mg/day; however, a supplement can be added if needed.
  • For improving learning and thinking skills in iron-deficient adolescents: 650 mg ferrous sulfate twice daily.
  • For cough caused by ACE inhibitors: 256 mg ferrous sulfate daily.
  • For restless legs syndrome (RLS): Ferrous sulfate 325 mg twice daily for 12 weeks.
INJECTED INTO THE VEIN:
  • For anemia caused by chronic disease: 2232 mg iron given by IV over 6 months to 1020 mg given by IV over 1 week have been used.
  • For heart failure: Ferric carboxymaltose (similar to iron sucrose, Venofer) 200 mg has been given IV weekly until iron levels were normalized, and then 200 mg has been given IV monthly for 6-months.
The adequate intake (AI) of iron for infants 6 months of age and less is 0.27 mg/day. For older infants and children, the recommended daily allowances (RDAs) for iron are: Infants 7 to 12 months, 11 mg/day; children 1 to 3 years, 7 mg/day; 4 to 8 years, 10 mg/day; 9 to 13 years, 8 mg/day; boys 14 to 18 years, 11 mg/day; girls 14 to 18 years, 15 mg/day. For adults, the RDA for iron is 8 mg/day for men ages 19 and older, and women ages 51 and older. For women 19 to 50 years, the RDA is 18 mg/day. For pregnant women, the RDA is 27 mg/day. For breast-feeding women, the RDA is 10 mg/day for ages 14 to 18 years, and 9 mg/day for ages 19 to 50.

Tolerable Upper Intake Levels (UL), the highest intake at which no unwanted side effects are expected, for iron are: infants and children birth to age 13, 40 mg/day; people age 14 and older (including pregnancy and breastfeeding), 45 mg/day. UL recommendations do not apply to people under medical supervision for iron deficiency.

There are many forms of iron supplements which contain different amounts of elemental iron: 1 gram of ferrous gluconate = 120 mg elemental iron (12% iron); 1 gram of ferrous sulfate = 200 mg elemental iron (20% iron); 1 gram of ferrous fumarate = 330 mg elemental iron (33% iron). The effectiveness and side effects are similar for these different forms when used in equal doses of elemental iron.

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Reviewed on 3/29/2011 12:35:40 PM

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