You know calcium is good for bones, but it may also reduce the risk of preeclampsia or high blood pressure during pregnancy, a condition that can lead to pregnancy complications, says Greenhouse. Most prenatals have some, but not all, of your daily calcium. That’s OK, says Carolyn Dean, MD, ND, author of The Complete Natural Medicine Guide to Women’s Health, as supplement forms are poorly absorbed. You’re better off getting the rest from dairy, soy, almonds and dark leafy greens. Have at least three servings of calcium-rich foods each day and look for 1,200 to 1,500 mg in your prenatals.