The Benefits of Prenatal Vitamins

by Mona Saint MD

What happens when you don’t take the prenatal vitamins? What happens to the child?

This is a great women’s health and pregnancy question as many women don’t know they are pregnant in the first trimester, or are so nauseated it makes it hard to take prenatal vitamins.

One of the most important components in a prenatal vitamin is folic acid. This vitamin help prevent malformations of the spine (neural tube defects like spina bifida), skull, and brain and 800 mcg  is the minimum recommended pregnancy dosage. The tricky part is that the neural tube closes about 2-4 weeks after conception, so often you don’t even know you are pregnant and may not have started a prenatal vitamin. We recommend that all women of childbearing age take a multivitamin or prenatal vitamin daily, since 50% of pregnancies are unplanned. If you have not been taking folic acid and just found out you are pregnant, the good news is that most of the time it is okay and the overall risk of neural tube defects is low. Folic acid has also been shown to reduce other congenital abnormalities and may decrease the risk of abruption (the placenta separating from its attachment to the uterus). If you are having significant nausea and cannot tolerate prenatals in the first trimester, a folic acid supplement can be taken alone and is usually well tolerated. Foods that are naturally rich in folic acid include: leafy green vegetables (like spinach and turnip greens), asparagus, broccoli, peas, fruits (like citrus fruits and juices), dried beans, and liver.(1) Folic acid is also added to breakfast cereals, breads, flours, pasta and rice.

Another important ingredient in prenatal vitamins is iron, which often is deficient during pregnancy and is the leading cause of pregnancy anemia (decreased oxygen in the red blood cells). Iron is important for fetal and placental development and to help with boosting maternal red blood cells. The recommended intake is 30 mg per day during pregnancy which is in most prenatal vitamins. (2) The most common symptom of mild anemia is fatigue.  Severe anemia can result in lower oxygenation to the placenta and baby and can cause: decreased fetal growth, decrease amniotic fluid, negative effects the fetal heart rate pattern, and may increase prematurity and stillbirths, and increase maternal risk. (2). Fortunately, most pregnant women have mild anemia, which can be improved with iron, as directed by your doctor. Iron rich foods include: meats – beef, pork, lamb, liver, and other organ meats, poultry – chicken, duck, turkey, liver (especially dark meat), fish – shellfish, including clams, mussels, and oysters, sardines, anchovies, leafy greens of the cabbage family, such as broccoli, kale, turnip greens, and collards, legumes, such as lima beans and green peas; dry beans and peas, such as pinto beans, black-eyed peas, and canned baked beans yeast-leavened whole-wheat bread and rolls, and iron-enriched white bread, pasta, rice, and cereals.(3)

Calcium is another important component of prenatal vitamins and helps with fetal bone development, and the needs are highest in the third trimester. The recommended pregnancy amount needed is 1000 mg a day-which can come from prenatal vitamins (these typically contain about 200 mg), a calcium rich diet, and calcium supplements. Calcium rich foods include milk, yogurt, and cheese.

DHA has been found to help with fetal and newborn brain development and is now included in most prescription prenatal vitamins. Usually at least 200 mg of DHA per day are recommended. If you are taking an over the counter prenatal, this does not contain DHA, so we recommend adding a supplement like Expecta so that you get this DHA. DHA is also found in fish, fortified foods like DHA supplemented eggs, and flaxseed.

Other ingredients in prenatal vitamins include Vitamins A through E and certain minerals. One note is to avoid taking any herbal supplements during pregnancy or extra vitamins without checking with your doctor because herbals aren’t well regulated and excessive dosages of vitamin as well as herbal supplements can cause fetal risks. Since most of us cannot get enough of these important vitamins and minerals in our diets, the safest and easiest thing to do is take a daily prenatal when trying to conceive and a multivitamin or prenatal vitamin if you not trying to conceive.

1. NIH Factsheet
3. University of Chicago Medical Center