About this ingredient
Ingredients
Ferrous refers to iron in the Fe²⁺ (ferrous) form, which is widely used in dietary supplements. Common ferrous iron compounds include ferrous sulfate, ferrous gluconate, and ferrous fumarate. These compounds contain different amounts of elemental iron, so the actual iron provided by a supplement depends on the specific compound and formulation.
Ferrous iron is the Fe²⁺ form of iron and is commonly used in nutritional supplements. Iron is an essential mineral involved in hemoglobin formation and oxygen transport, as well as normal muscle metabolism and other physiological processes.
Common ferrous compounds used in supplements include ferrous sulfate, ferrous gluconate, and ferrous fumarate. Although these compounds all provide iron, their elemental iron concentrations differ. For example, NIH notes that ferrous fumarate contains about 33% elemental iron by weight, ferrous sulfate about 20%, and ferrous gluconate about 12%.
Ferrous iron is found in standalone iron supplements, multivitamins, mineral formulas, and nutritional products. Because the amount of elemental iron varies by compound, consumers should check the product label for the actual elemental iron amount and recommended serving.