The Role of Magnesium in Normal and Abnormal Pregnancy

Abstract

The formation of new tissue (maternal and fetal) during pregnancy requires higher magnesium intakes than that of the normal nonpregnant woman of comparable age. The most recent recommended dietary allowances in the United States and Canada is 450 mg/day (Food and Nutrition Boards, 1968), a figure that is probably based largely on magnesium balance determinations and calculations done with adult pregnant women from 1914–1942. The general statement that the dietary magnesium during pregnancy should substantially exceed the amount required by other adults has led to the selection of 450 mg/day as reasonable, exceeding that recommended for adolescent and young adult women in the United States by 100 mg/day and exceeding the amount recommended in Canada for women over 22 by 150 mg/ day. Since adolescent children require much higher magnesium intakes to meet their own growth and maturation needs, it is questionable whether the same amount deemed necessary for the mature pregnant woman is sufficient for a teenaged pregnant girl. Even the amount generally considered sufficient, but rarely met by the American woman, whether or not she is pregnant (Seelig, 1964; N. Johnson and Phillips 1976/1980; Ashe et al., 1979), should be reevaluated.