Carbonyl Iron vs. Ferrous Iron

Carbonyl Iron vs Ferrous Iron

Carbonyl less toxic and better tolerated than ferrous iron

Slower to absorb—Ferrous iron is absorbed shortly after it is ingested. However, carbonyl iron is only absorbed at the rate that gastric acid is produced, since gastric acid is required to make carbonyl iron soluble.1,2 This means that carbonyl iron enters your system much more gradually than other types of iron that can dissolve rapidly.2

Less toxic than ferrous iron—Researchers believe that this slow rate of solubilization minimizes the toxicity of carbonyl iron.1 In fact, studies have shown that carbonyl iron is far less toxic than other forms of iron, even at high doses. Patients taking carbonyl iron can tolerate 10 to 150 times the standard dose of ferrous sulfate iron, while still having nearly the same side effects.1,3 Due to its slower absorption, carbonyl iron may have an advantage over therapy with iron salts by substantially reducing or eliminating the risk of poisoning in children.1

1 Gordeuk VR, Brittenham GM, McLaren CE, Hughes MA, Keating LJ. Carbonyl iron therapy for iron deficiency anemia. Blood. 1986;67(3):745-752.

2 Brittenham GM, Klein HG, Kushner JP, Ajioka RS. Preserving the national blood supply. Hematol Am Soc Hematol Educ Program. 2001:422-432.

3 Gordeuk VR, Brittenham GM, Hughes M, Keating LJ, Opplt JJ. High-dose carbonyl iron for iron deficiency anemia: a randomized double-blind trial. Am J Clin Nutr. 1987;46(6):1029-1034.