Supplementing Your Health: Folic Acid for Pregnancy

By Amichai Perlman, PhD, PharmD
Medically reviewed checkmarkMedically reviewed
May 13, 2021

K Health’s Pharma expert, Dr. Amichai Perlman, on Supplementing Your Health: folic acid before, during, and after pregnancy.

The dazzling array of vitamins and dietary supplements featured in pharmacies everywhere often promise natural cures to diseases and ailments, and general enhancement of one’s health, intelligence, and wellbeing. We all know many of these claims are inaccurate, exaggerated, or just untrue, however it is also difficult to fact-check their basis.

Through our Supplementing Your Health series, we highlight and discuss the evidence backing vitamins and supplements that work, as well as the many that do not. This information can help improve our health and well being, as well as better manage the time and money we invest in our health.

Supplements That Work: Folic Acid for Pregnancy

Few vitamins and dietary supplements have proven health benefits for people without significant dietary deficiency. One of these, which is widely endorsed by major medical organizations and public health authorities, is folic acid for women of childbearing ages.

Evidence Suggest It Does, In Fact, Reduce Birth Defects

Folic acid, also known as vitamin B9, is needed by all of the cells in our body for growth and development. Several large randomized controlled trials have proven that the use of folic acid supplements during pregnancy reduces birth defects of the brain and spine called “neural tube defects” by 70-90%. There is evidence suggesting folic acid supplements reduce the risk of some other birth defects as well, however this is less conclusive.

These trials have led to the recommendations encouraging use of daily supplements of 0.4 to 0.8 mg (400 to 800 micrograms) at least 1 month before pregnancy. This is because the defects in the neural tube (the part of the developing baby that becomes the brain and spinal cord) occur early in pregnancy, before you know that you’re pregnant. In fact, because as many as 50% of pregnancies are unplanned, most authorities, including the US Preventive Services Task Force, recommend folic acid supplementation for “all women who are planning or capable of pregnancy.”

Natural Sources of Folic Acid

Folic acid is present naturally in the form of “folate” in several foods, including beef liver, leafy vegetables, peas and beans, avocados, eggs, and milk. It is also added to fortify certain foods, including flour, pasta, breads, cereals, cornmeal, and rice, as well as to some birth control pills. The policy to fortify foods has been shown to reduce the rate of neural tube defects in the general population. However a conscious effort is needed to ensure the recommended daily intake of folic acid even if you eat foods that have folic acid in them, which is why daily supplements containing folic acid are generally the surest way to achieve this goal.

Know Your Dose

Higher doses of folic acid may be recommended in women with certain medical conditions, including conditions predisposing them to reduced absorption of folic acid (such as celiac, inflammatory bowel disease, and bariatric surgery), when taking some medications (such as some antiseizure medications), or when there are other risk factors for birth defects such as a family history of neural tube defects. However, one should consult a doctor before taking higher doses than those generally recommended.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Amichai Perlman, PhD, PharmD

Dr. Perlman is a clinical pharmacist and pharmacoepidemiologist, with over 10 years of experience advising patients and clinicians on medication use, personalization, and safety. He has extensively published peer-reviewed research addressing medication safety.