Iron supplements, also known as iron salts and iron pills, are a number of iron formulations used to treat and prevent iron deficiency including iron deficiency anemia. For prevention they are only recommended in those with poor absorption, heavy menstrual periods, pregnancy, hemodialysis, or a diet low in iron. Prevention may also be used in low birth weight babies. They are taken by mouth, injection into a vein, or injection into a muscle. While benefits may be seen in days, up to two months may be required until iron levels return to normal.Common side effects include constipation, abdominal pain, dark stools, and diarrhea. Other side effects, which may occur with excessive use, include iron overload and iron toxicity. Ferrous salts used as supplements by mouth include ferrous fumarate, ferrous gluconate, ferrous succinate, and ferrous sulfate. Injectable forms include iron dextran and iron sucrose. They work by providing the iron needed for making red blood cells.Iron pills have been used medically since at least 1681, with an easy-to-use formulation being created in 1832. Ferrous salt is on the World Health Organizations List of Essential Medicines. Ferrous salts are available as a generic medication and over the counter. Slow release formulations, while available, are not recommended. In 2017, ferrous sulfate was the 92nd most commonly prescribed medication in the United States, with more than eight million prescriptions.
Proferrin ES and Proferrin Forte) can be used when regular iron supplements such as ferrous sulfate or ferrous fumarate are not tolerated or absorbed. A clinical study demonstrated that HIP increased serum iron levels 23 times greater than ferrous fumarate on a milligram-per-milligram basis.Another alternative is ferrous glycine sulfate or ferroglycine sulfate, has less gastrointestinal side-effects than standard preparations such as iron fumarate. It is unusual among oral preparations of iron supplements in that the iron in this preparation has very high oral bioavailability, especially in the liquid formulation. This option should be evaluated before resorting to parenteral therapy. It is especially useful in iron deficiency anemia associated with autoimmune gastritis and Helicobacter pylori gastritis, where it generally has satisfactory effect.Since iron stores in the body are generally depleted, and there is a limit to what the body can process (about 2–6 mg/kg of body mass per day; i.e. for a 100 kg/220 lb man this is equal to a maximum dose of 200–600 mg/per day) without iron poisoning, this is a chronic therapy which may take 3–6 months.Due to the frequent intolerance of oral iron and the slow improvement, parenteral iron is recommended in many indications. By injection
Iron therapy (intravenously or intramuscular) is given when therapy by mouth has failed (not tolerated), oral absorption is seriously compromised (by illnesses, or when the person cannot swallow), benefit from oral therapy cannot be expected, or fast improvement is required (for example, prior to elective surgery).