A prenatal vitamin is a daily supplement designed to deliver the nutrients you need most when pregnant, in amounts that are hard to reach from food alone. It is a safety net for the handful of nutrients where even a good diet tends to fall short: folate, iron, DHA, calcium, vitamin D, and choline. The vitamin aisle makes this feel complicated. The science behind it is not.
When should I start taking prenatal vitamins?
Before you conceive, ideally. The neural tube, which becomes your baby’s brain and spinal cord, closes in the first four weeks of pregnancy, often before a missed period. Folate is what protects that process, and it needs to be in your system already. If you are trying, or even just not preventing, start a prenatal now. Any woman who could become pregnant benefits from a daily supplement with at least 400 micrograms of folic acid for this reason.
If you just found out you are pregnant and have not been taking one, start today. Most women who begin in the first trimester do just fine.
Most important vitamins for pregnancy
Folate leads the list. It prevents serious birth defects of the brain and spine and supports the rapid cell growth of early pregnancy. Leafy greens, beans, lentils, citrus, and fortified grains are good sources, but the supplement is what gets most women to the amount pregnancy requires. Some prenatals use methylfolate instead of folic acid. Either form works for most women.
Iron builds the extra blood volume your body makes during pregnancy and carries oxygen to your baby. Your need for iron roughly doubles in pregnancy, and low iron is the most common nutrient shortfall we see, especially in the third trimester. Red meat, poultry, beans, and fortified cereal help. Vitamin C improves iron absorption, while coffee, tea, and calcium taken at the same time reduce it.
