Prenatal vitamins are a variety of vitamins created with the specific nutrients necessary to sustain both a mother and fetus during the nine months of pregnancy. Prenatal vitamins are also recommended for mothers who are breastfeeding, to ensure they are still receiving the correct amount of nutrients for themself and their baby. Multivitamins are designed with the daily recommended doses of vitamins and occasionally minerals for a healthy adult. While multivitamins are beneficial for adults, they are not recommended for pregnant women because they contain insufficient amounts of some nutrients and higher than recommended amounts of others.
Calcium promotes bone and circulatory development in fetuses. Prenatal vitamins typically contain 300 mg per day.
A study published by the Center for Human Nutrition, Department of International Health and The Johns Hopkins School of Hygiene and Public Health reported that taking zinc supplements during pregnancy positively impacts "fetal neurobehavioral development."
According to the Mayo Clinic, "Folic acid helps prevent neural tube defects — serious abnormalities of the brain and spinal cord. Folic acid may also decrease the risk of preterm delivery and low birth weight." While folic acid is available in multivitamins, multivitamins do not contain the necessary amount for pregnant women of 1 mg per day.
Multivitamins contain too much vitamin A to be healthy for pregnant women. Large amounts of vitamin A are associated with birth defects, including open abdominal cavities and heart defects.
According to a study by the Cochrane Pregnancy and Childbirth Group Trials Register, increased amounts of vitamin C are essential in pregnancy to prevent pre-eclampsia, anemia and low birth weight. For this reason, prenatal vitamins are packed with typically 400 percent of the daily dose of vitamin C.
A study published by the Journal for Progressive Lipid Development found that "children whose mothers were supplemented with DHA during pregnancy had improved cognitive function, visual acuity, and overall improved brain development."