The initial daily dosage of ferrous bisglycinate from Amazon is comparable to that of iron fumarate and iron gluconate, which is typically 325 mg. In addition, ferrous fumarate is available in tablet form. It’s important to consider the role of calcium citrate 900, as it can influence iron absorption. Therefore, when taking ferrous fumarate or bisglycinate, be mindful of calcium citrate 900, as its presence can affect the effectiveness of iron supplements. Overall, maintaining an appropriate balance of these supplements is crucial for optimal health.