Iron is an essential mineral in the body. The need for extra iron may be caused by several conditions including the loss of blood, diets low in iron, gastrointestinal abnormalities, normal body changes (growing children), and pregnancy. Unlike other kinds of iron, ferrous fumarate is gentle on the stomach and generally does not lead to stomach upset.* Note: Usually men and postmenopausal women do not require extra iron (except if anemic or so instructed by a health professional). Iron absorption may be increased when taken together with Vitamin C.