Until 1999, in the United States, the vast majority of iron supplements were made with ferrous iron salts. That is, a positively charged iron and its counter ion (negatively charged counterpart). Popular and common counter ions are sulfate, gluconate and fumarate. Fumarate and Gluconate are carbon containing carboxylic acids.
Typically, the way these compounds are made is that pure iron, usually as iron filings which are dissolved in sulfuric or hydrochloric acid. Once dissolved, the counter ion is added and the pH is slowly adjusted back to neutrality. As this happens the iron is no longer soluble so it binds to the counter-ion and drops out of solution. The slurry is then dehydrated and the remaining dry matter is the iron salt.
The manufacture of these products gives an important clue as to how they work in the body. Once ingested, it is imperative that the stomach contains acid to dissolve the iron salt. If a person is taking antacids or H2 blockers such as cimetidine (Tagamet), their stomach will be "achlorhydric" - no acid in the stomach and the iron salt will not dissolve. As such the person will derive no benefit from the iron supplement.
There are a few specialty pharmacies around the country that make special iron tonics or capsules. The tonics are made as solutions that keep the iron soluble. This is done so that people won't have to worry about whether the pills dissolve in their stomachs - it's already in solution. These present some danger however because if the whole bottle is consumed by a child, a very real risk of overdose exists. Because the manufacturers know this, they generally make them with very low iron concentrations.
Other pharmacies add things like "intrinsic factor" or liver extract. Liver extract contain ferritin as well as some heme iron. The amount of iron in these preparations bound to heme is generally less than 1/2 milligram.
Intrinsic Factor (IF) was so named because of its essential role in helping vitamin B12 perform in its role to produce red blood cells. IF is present in gastric juice and performs its duty by binding to B12. Once bound, IF changes and becomes less susceptible to digestion and thereby protects B12 and allows for its absorption from gastric juice.
Most of us can get sufficient amounts of iron from daily diets that include a moderate amount of meat, because meat contains heme, which is easily absorbed by the body. However, some people need supplemental iron. Finding the right type and dose is an individual decision made between the patient and the physician.
Iron pills should be taken 2 hours before or after other medications. Iron can inhibit the effectiveness of thyroid medications, antibiotics and some antidepressant drugs. Foods and substances that can interfere with the absorption of iron include calcium, tannins, which are found in coffee, tea, grapes, red wine, purple or red rice, and bran fiber or chocolate. Iron supplementation is best taken two hours after consuming these substances.
Also, oral iron might be improved by taking a small amount of supplemental zinc. In one Japanese study, Dr. Soruku Nishiyama,of Kumamota University School of Medicine demonstrated that "...supplementing with both minerals (zinc and iron) is more effective than either alone...and that some prenatal anemia is due to a deficiency of zinc, not iron."
In this study, Dr. Nishiyama placed 38 pregnant women into three groups: 11 took 34 mg/day zinc, 10 received 100 mg iron, and 17 took both supplements for eight weeks. Taking either zinc or iron alone did not change the average RBC counts, but the combination did; it also raised average hemoglobin levels from 10.3 to 11.0g/dL.
The amount of elemental iron contained in iron pills will vary. A 325-milligram (mg) supplement is probably made of ferrous fumarate or gluconate and actually contains only 100 mgs of elemental iron per pill, the balance of the mass being the fumarate or gluconate counter iron.
Carbonyl iron is often used by physicians because it is less toxic to children who might take an accidental overdose. Since sugar increases the absorption of iron, iron gluconate generally found in liquid supplements may be better absorbed with fewer side effects for some. Iron pills that contain heme iron such as VitaHeme® or Proferrin® and are claimed by patients to be well tolerated. Renal disease patients who took Proferrin®, report that there were fewer side effects, such as gastro-intestinal discomfort (nausea, vomiting). Since heme is more easily absorbed, smaller amounts of iron are contained in a single dose. Note that VitaHeme® is in powder form, which may result in inconsistent dosing; this product may no longer be available.
Proferrin®: Performance studies indicate that iron absorption rates are between 15% and 20% without erythropoietin (EPO) therapy and as high as 30% with EPO therapy even in patients with high serum ferritin values (>600 ng/ml). In one study, the change in serum iron from Proferrin® was nearly 23 times greater than from an identical dose of ferrous fumarate. Also, study participants were able to tolerate up to 60 mgs per dose on an empty stomach with fewer gastrointestinal side effects; a common complaint from patients taking traditional oral iron preparations. An additional benefit of heme iron supplementation is that patients can take it with their meals, unlike ionic iron preparations, which must be taken on an empty stomach between meals. The FDA allowed the marketing of Proferrin® in the United States in late 2000. It is available in both an over-the-counter at most Walgreen's Drugstores and prescription form.
Products: Listing of these products is for information purposes only; consult with a physician before taking supplemental iron.