Pregnancy health

Why you need folic acid during—and before—pregnancy

Supplementing with folic acid is a must in pregnancy. Here's what you need to know.

Why you need folic acid during—and before—pregnancy

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When you’re pregnant, or thinking about becoming pregnant, you want to do everything you can to make sure your baby is healthy. Part of that includes ensuring you get enough folate, a vitamin that plays a vital role in the first month of pregnancy.

What is folic acid?

Folate is found in many foods we eat daily, like avocado, nuts, beets, cooked broccoli, spinach, wheat germ and legumes such as lentils, black beans and kidney beans. It is also called vitamin B9. Folic acid is the synthetic, or man-made, version of folate.  In pregnancy, folate is important for the development of the brain, spinal cord and skull, especially in the first four weeks after conception.

Too little folate in those first few weeks is linked to neural tube defects that occur as the fetus develops, conditions which can be life-limiting, or even fatal. The most common neural tube defect is spina bifida, where the spinal cord doesn’t fuse all the way, says Deepa Upadhyaya, a registered midwife and associate professor in the midwifery program at Mount Royal University in Calgary. The second most common is anencephaly, where parts of the brain and skull don’t develop.

While this all sounds pretty scary, there is good news. In the late ‘90s, Canada started both fortifying white flour with folic acid and recommending women supplement with folic acid. Since then, the number of babies born with spina bifida has fallen by more than 50 percent. “In combination, these measures have heavily reduced the rate of neural tube defects,” says Upadhyaya.

It’s not hard to get enough folic acid these days. “Prenatal vitamins have folic acid in them, and most multivitamins do, too.” Upadhyaya also recommends eating folate-rich foods before and during pregnancy, in addition to that folic acid supplement.

How much folic acid should you take?

The recommended dose of folic acid is 0.4 mg daily, starting two to three months prior to conception and continuing for the first 12 weeks of pregnancy, says Upadhyaya. (While it’s not vital after those first 12 weeks, it’s safe to continue taking it throughout your pregnancy.) Any prenatal multivitamins in Canada will have at least that amount. Many multivitamins also contain folic acid, but read the label to be sure.

However, an estimated 50 per cent of pregnancies in Canada are unplanned, meaning anyone who could get pregnant (even by accident) should supplement with folic acid, says Lalitha Taylor, a registered dietitian in Edmonton.


“Because there is such a high prevalence of unintended pregnancies, folic acid is not only recommended for women who are trying to become pregnant, but for all women of reproductive age,” says Taylor.

However, stick to the recommended 0.4 mg, unless your health care provider tells you otherwise. Some prenatal multivitamins have more, so look at the label and choose accordingly. In most cases, there’s no advantage to taking extra folic acid and it may even be harmful.

Occasionally, a doctor or midwife might recommend more than the standard dose of folic acid before trying to conceive. This would include if you’ve had a previous pregnancy with a neural tube defect, a family history of neural tube defects, or any of the following conditions: obesity, pre-existing diabetes or liver disease.

Can folic acid help with morning sickness?

In some cases, women have trouble getting their folic acid supplement due to morning sickness. Upadhyaya says if nausea and vomiting is preventing you from keeping down your prenatal multivitamin, the first stop should be talking to your midwife or doctor.

“See your pregnancy care provider and get the nausea and vomiting under control,” she says. “We can prescribe things, like Diclectin.” (However, there are also questions about how effective Diclectin actually is.) Upadhyaya says it’s also important to talk to your care provider to rule out hyperemesis gravidarum, severe vomiting that may require more medical care.


Since the iron component of a prenatal multivitamin may contribute to nausea and constipation, Taylor, who was diagnosed with hyperemesis gravidarum during her own pregnancy, says switching to a folic acid-only supplement can be an option—as long as your doctor or midwife OKs it. “That’s what my doctor had me do, I stopped my prenatal vitamin and had a single folic acid supplement until I could tolerate restarting my prenatal in the second trimester,” she says.

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