Is ferrous fumarate equivalent to elemental iron? Firstly, elemental iron is present in ferrous fumarate. When comparing iron bisglycinate and ferrous ascorbate, ferrous fumarate serves as an important alternative. Additionally, it’s essential to consider the amount of calcium in mg when evaluating these iron supplements. Ferrous fumarate contains iron that can be absorbed effectively, while also being mindful of the calcium in mg present in the dietary context. Therefore, understanding the relationship between ferrous fumarate and elemental iron, along with the impact of calcium in mg, is crucial for making informed choices about iron supplementation.