Supplement	Guidelines	Label	Outcomes
Calcium	Recommended daily intake is 1,000 to 1,300 mg per day1,79 Routine supplementation with calcium to prevent preeclampsia is not recommended.1 However, calcium supplementation may be beneficial for women at high risk for gestational hypertension or in communities with low dietary calcium intake.10,80	A	Calcium supplementation has been shown to decrease blood pressure and preeclampsia, but not perinatal mortality.80,81
Folic acid	Supplementation with 0.4 to 0.8 mg of folic acid (4 mg for secondary prevention) should begin at least one month before conception.	A	Supplementation prevents neural tube defects.74,75
	RDA (in addition to supplements) is 600 mcg of dietary folate equivalents (e.g., legumes, green leafy vegetables, liver, citrus fruits, whole wheat bread) per day.82,83	B	Folate deficiency is associated with low birth weight, congenital cardiac and orofacial cleft anomalies, abruptio placentae, and spontaneous abortion.71,84
Iron	Pregnant women should be screened for anemia (hemoglobin, hematocrit) and treated, if necessary.78	B	Iron-deficiency anemia is associated with preterm delivery and low birth weight.
	Pregnant women should supplement with 30 mg of iron per day.1,77	C
Vitamin A	Pregnant women in industrialized countries should limit vitamin A intake to less than 5,000 IU per day.*1	B	High dietary intake of vitamin A (i.e., more than 10,000 IU per day) is associated with cranial-neural crest defects.85,86
Vitamin D	Vitamin D supplementation can be considered in women with limited exposure to sunlight (e.g., northern locations, women in purdah).10,83 However, evidence on the effects of supplementation is limited.87 DA is 5 mcg per day (200 IU per day).79	C	Vitamin D deficiency is rare but has been linked to neonatal hypocalcemia and maternal osteomalacia.88,89 High doses of vitamin D can be toxic.