Fiiron supplements contain gluconate, while ferrous fumarate provides elemental iron in the form of ferrous gluconate at a dosage of 300 mg. Additionally, there is a comparison between iron bisglycinate and ferrous fumarate versus ferrous sulfate, which is highlighted by GoodRx. It’s worth noting that calcium citrate tablets without vitamin D can be an essential part of a balanced supplement regimen. Incorporating calcium citrate tablets without vitamin D can help support overall health, especially when considering the benefits of iron supplements like ferrous fumarate. For those looking to improve their iron levels, understanding the differences between these supplements and the role of calcium citrate tablets without vitamin D is crucial.