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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. Iron can be found in foods like meat, fish, tofu, beans, spinach, cereal and other foods.
Iron is most commonly used for preventing and treating anemia caused by low iron levels. It is also used for anemia caused by chronic disease, pregnancy, or kidney problems.
- Anemia of chronic disease. Oral and intravenous iron in combination with epoetin alfa are effective for treating anemia of chronic disease.
Login for details - Iron deficiency anemia. Oral and intravenous iron are effective for treating or preventing iron deficiency anemia. The benefits of iron supplementation in people with iron deficiency without anemia are unclear.
Login for details - Pregnancy-related iron deficiency. Oral iron is effective for preventing pregnancy-related iron deficiency.
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- Breath-holding attacks. Oral iron seems to be effective for reducing the frequency of breath-holding attacks in children with iron deficiency.
Login for details - Cognitive function. Oral iron seems to be effective for improving cognitive function in children and adolescents with iron deficiency.
Login for details - Heart failure. Intravenous iron seems to be effective for improving recovery in patients with heart failure and iron deficiency. Oral iron may not be effective.
Login for details - Restless legs syndrome (RLS). Oral and intravenous iron seem to be beneficial for RLS. The American Academy of Neurology recommends a combination of oral ferrous sulfate and vitamin C or intravenous ferric carboxymaltose for patients with RLS.
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- Athletic performance. Oral iron does not seem to improve athletic performance.
Login for details - Child growth. Oral iron does not seem to be beneficial for child growth.
Login for details - Preterm labor. Oral iron does not seem to prevent preterm labor and may actually increase the risk in malaria-endemic regions.
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- ACE inhibitor-induced cough. It is unclear if oral iron is beneficial in patients with this condition.
Login for details - Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral iron is beneficial in children with ADHD.
Login for details - Child development. It is unclear if oral iron is beneficial for improving development in non-anemic children.
Login for details - Esophageal cancer. It is unclear if oral iron is beneficial for esophageal cancer prevention.
Login for details - Fatigue. It is unclear if oral iron is beneficial in patients with fatigue due to iron deficiency without anemia.
Login for details - Postpartum depression. It is unclear if oral iron is beneficial for postpartum depression.
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Iron helps red blood cells carry oxygen from the lungs to cells all over the body. Iron also plays a role in many important functions in the body.
When taken by mouth: Iron is LIKELY SAFE for most people when it is taken by mouth in appropriate amounts. It can cause side effects such as 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 can absorb 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 iron 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, the body may not be able to absorb these products as well.
Liquid iron supplements may blacken teeth.
When given by IV: Iron is LIKELY SAFE for most people when it is given by IV in appropriate amounts.
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. Higher doses cause stomach and intestinal side effects such as nausea and vomiting and may even cause preterm birth in some women. Higher doses of iron can cause high levels of hemoglobin in the blood. High hemoglobin levels at the time of delivery are associated with bad pregnancy outcomes.Children: High doses of iron are LIKELY UNSAFE, 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 a child has taken more than the recommended amount of iron, call your healthcare professional or the nearest poison control center immediately.
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.
Hemoglobin diseases: Taking iron might cause iron overload in people with these conditions. If you have a hemoglobin disease, do not take iron unless directed by your healthcare provider.
An inherited disorder that affects the formation of blood vessels (hereditary hemorrhagic telangiectasia or HHT): Taking iron might increase the risk of nosebleed in patients with HHT. Use with caution.
Premature infants: Giving iron to premature infants with low blood levels of vitamin E can cause serious problems. Low levels of vitamin E should be treated before giving iron. Talk with your healthcare provider before giving iron to a premature infant.
Antibiotics (Quinolone antibiotics)
Interaction Rating=Moderate Be cautious with this combination.
Iron might decrease how much antibiotic the body absorbs. Taking iron along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction take iron two hours before or two hours after taking antibiotics.
Some of these antibiotics that might interact with quercetin 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.
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.
Iron can decrease how much bisphosphate the body absorbs. Taking iron along with bisphosphates can decrease the effectiveness of bisphosphates. 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.
Chloramphenicol
Interaction Rating=Minor Be watchful with this combination.
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.
Levodopa
Interaction Rating=Moderate Be cautious with this combination.
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.
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.
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.
Iron might decrease how much mycophenolate mofetil (CellCept) the body absorbs. Taking iron along with mycophenolate mofetil (CellCept) might decrease the effectiveness of mycophenolate mofetil (CellCept). To avoid this interaction take iron at least two hours after mycophenolate mofetil (CellCept).
Penicillamine (Cuprimine, Depen)
Interaction Rating=Moderate Be cautious with this combination.
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.
Acacia: Acacia forms an insoluble gel with some forms of iron. It isn't known whether this leads to a significant interaction when the two are ingested together.
Beta-carotene: Beta-carotene may help the body take in (absorb) iron from iron-fortified wheat and corn flour, and rice. But taking extra beta-carotene probably wouldn't make much difference in iron absorption unless levels of beta-carotene are too low.
Calcium: Calcium makes it harder for the body to absorb iron either from food or supplements. In people who have enough stored iron, this probably isn't a problem. However, if you are iron deficient or might become iron deficient, minimize this interaction by separating your intake of calcium and iron. Don't take calcium supplements at mealtime or when you take iron supplements.
Lactobacillus: A probiotic species called Lactobacillus plantarum might increase how much iron the body can absorb.
Soy: Soy protein seems to reduce the body's ability to take in iron. If you have low iron levels, choose fermented soy products like tempeh, which might not have the same effect. However, the importance of the interaction between soy and iron is not known.
Vitamin A: Vitamin A appears to be involved in moving iron from where it is stored in the body to red blood cells developing in the bone marrow. There, iron is used to build hemoglobin, the molecule in red blood cells that carries oxygen. Giving vitamin A supplements seems to improve iron levels in people whose iron levels are too low. Developing research suggests that vitamin A and beta-carotene may improve iron absorption from iron-fortified wheat and corn flour, and rice. It's unlikely that giving vitamin A supplements would have significant effects on iron status in people who have enough vitamin A to start with.
Vitamin C: Taking vitamin C with iron in the diet together helps the body absorb the iron. It doesn't matter whether the vitamin C comes from food or a supplement. However, taking a vitamin C supplement to improve the absorption of iron from a supplement probably isn't necessary for most people, especially if their diet contains plenty of vitamin C.
Zinc: Under some circumstances iron can interfere with how the body absorbs zinc, and vice versa. However, food stops the interaction. To get maximum benefit from zinc or iron supplements, it's a good idea to take them with food.
Calcium-containing foods: Dairy products such as milk and cheese can reduce the absorption of iron from food and supplements. If you are taking iron because you have low iron levels, take iron supplements with a meal that is low in dairy products if possible. People may say you'll get the best absorption of iron on an empty stomach, but this increases the risk of stomach irritation. Don't risk it. You're better off taking iron with a low-calcium meal.
Food: Taking iron with food can decrease how much iron is absorbed by the body by 40% to 50%. For best absorption, iron should be taken on an empty stomach. However, some people may not be able to tolerate this due to side effects such as upset stomach or nausea. If iron needs to be taken with food to reduce side effects, avoid dairy foods, coffee, tea, or cereals.
Hot drinks: Taking iron supplements with coffee or tea can reduce the amount of iron the body absorbs. These beverages can even reduce the amount of iron the body absorbs from food. These effects might contribute to anemia caused by low iron levels, especially in people at risk of anemia.
The following doses have been studied in scientific research:
ADULTS
BY MOUTH:
- For low levels of healthy red blood cells (anemia) due to iron deficiency: 50-100 mg of elemental iron three times daily for 3 months up to 6 months. Doses between 30-120 mg weekly have been used in adult women.
- For low iron levels in women who are pregnant: 20-225 mg of elemental iron daily have been used. The recommended dose is 45 mg daily.
- For a disorder that cause leg discomfort and an irresistible urge to move the legs (restless legs syndrome or RLS): Iron as ferrous sulfate has been taken at doses of 325 mg twice daily for 12 weeks.
- For low levels of red blood cells in people with a long-term illness (anemia of chronic disease): A total dose of 2232 mg of iron given by injection delivered over 6 months to 1020 mg given by IV over 1 week have been used.
- For heart failure: Iron as ferric carboxymaltose has been given by injection at doses of 200 mg weekly until iron levels are normal, followed by 200 mg by injection every month for 6 months.
BY MOUTH:
- For low levels of healthy red blood cells (anemia) due to iron deficiency: 4-6 mg/kg of iron per day divided into three doses for 3 months up to 6 months.
- For preventing low iron levels: The American Academy of Pediatrics recommends iron supplements for some children at risk of low iron levels.
- For breast-fed infants: 1 mg/kg/day elemental iron from ages 4-6 months.
- For Infants 6-12 months: 11 mg/day of iron from food or supplements.
- For pre-term infants: 2 mg/kg/day of iron for the first year until the baby is switched to formula or getting enough iron from food sources.
- For toddlers aged 1-3 years: 7 mg daily of iron f not getting enough iron from food sources.
- For memory and thinking skills (cognitive function) in adolescents: 650 mg ferrous sulfate twice daily.
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.
Atomic Number 26, Carbonate de Fer Anhydre, Citrate de Fer, Elemental Iron, Fe, Fer, Fer Élémentaire, Ferric Iron, Ferric Hydroxide Polymaltose, Ferric Orthophosphate, Ferric Oxide Saccharide, Ferric Sodium Citrate, Ferrous Carbonate Anhydrous, Ferrous Citrate, Ferrous Fumarate, Ferrous Gluconate, Ferrous Iron, Ferrous Pyrophosphate, Ferrous Succinate, Ferrous Sulfate, Ferrum Phosphoricum, Fumarate de Fer, Gluconate de Fer, Glycérophosphate de Fer, Heme Iron Polypeptide, Hierro, Iron Glycerophosphate, Iron Polysaccharide, Orthophosphate de Fer, Orthophosphate Ferrique, Numéro Atomique 26, Polypeptide de Fer de Heme, Pyrophosphate de Fer, Sulfate de Fer.
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