Menstrual bleeding is a common cause of iron deficiency anemia in women of child-bearing age. Women with menorrhagia (heavy menstrual periods) are at risk of iron-deficiency anemia because they are at higher-than-normal risk of losing a larger amount blood during menstruation than is replaced in their diet. Most women lose about 40 mL of blood per cycle. Iron is lost with the blood. Some birth control methods, such as pills and IUDs, may decrease the amount of blood, therefore iron lost during a menstrual cycle. Intermittent iron supplementation may be as effective a treatment in these cases as daily supplements and reduce some of the adverse effects of long term daily supplements.