Ferrous fumarate, which contains 86 mg of vitamin B complex, is available in a formulation of 305 mg of ferrous fumarate. It is important to note that ferrous fumarate, ferrous sulfate, and ferrous gluconate are similar in their iron content and benefits. Additionally, one can find formulations that include 800 mg of calcium citrate, which is beneficial for overall health. Incorporating 800 mg of calcium citrate in your supplement regimen can enhance the absorption of iron and other essential nutrients. Therefore, when considering iron supplements like ferrous fumarate, be sure to also look for those that provide 800 mg of calcium citrate for optimal effectiveness.