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.
How it works
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.
EffectiveAnemia 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.
Taking iron supplements is effective for treating and preventing iron deficiency and anemia caused by too little iron in the body.
Taking iron might reduce the risk of anemia caused by too little iron in the body when taken by women who are pregnant.
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.
Pregnancy and breast-feeding: Iron isLIKELY SAFEfor pregnant andbreast-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 isLIKELY UNSAFEwhen 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 badpregnancyoutcomes. Hemoglobin is themoleculein 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.
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).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).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) 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)
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
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.Methyldopa (Aldomet)
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.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)
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)
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.