Ferrous Sulphate

Ferrous sulfate is just one of many forms of the metal element iron.

In its natural state, the solid mineral resembles small crystals. The crystals are typically a shade of yellow, brown, or bluish-green — hence why ferrous sulfate is sometimes called green vitriol (1).

Supplement makers use multiple types of iron in dietary supplements. Aside from ferrous sulfate, the most common are ferrous gluconate, ferric citrate, and ferric sulfate.

Most types of iron in supplements are in one of two forms — ferric or ferrous. This depends on the chemical state of the iron atoms.

The body absorbs ferrous forms of iron better than ferric forms. Thus, healthcare providers often consider ferrous forms, including ferrous sulfate, to be the best choice for iron supplements.