Minerals known to be of major importance during pregnancy include calcium, copper, iodine, iron, magnesium, selenium, and zinc. Deficiencies in these minerals have been associated with complications of pregnancy, childbirth, or fetal development. This chapter considers each, by briefly discussing their physiological roles, and discussing how the symptoms of deficiency overlap. It also discusses the consequences of deficiencies using both animal and human models and considers how these might be best treated, if indeed they can. Mineral deficiencies have varied effects because of the wide range of roles they play. In pregnancy, the effects can be seen in both the mother and her fetus. The mother can suffer from pregnancy induced hypertension, anemia, preeclampsia, labor complications, and death. To meet the increased demand for the essential minerals during pregnancy and lactation, maternal physiology undergoes several alterations.