The Importance of Folic Acid and Intake Timing: A Crucial Nutrient in Preconception Care

For Those Desiring Pregnancy: The Power of Folic Acid for a Healthy Future

To women in their 20s and 30s, and their partners, Are you experiencing vague anxieties or questions like: "I want to have a baby in the future, but where do I even begin?" "What can I do now to prepare for pregnancy?"

I'm Dr. Takuma Sato, an obstetrician and gynecologist, and I'm here to illuminate a crucial first step towards a brighter future for you: preconception care. This involves men and women engaging with their health before planning pregnancy and adopting healthy lifestyle habits.

Specifically, we will focus on folic acid, the single most vital nutrient in this journey, explaining its role and optimal timing for intake, all based on robust scientific evidence.

What is Preconception Care? Why is Folic Acid So Critical?

Preconception care is a form of "health preparation" before pregnancy, aiming not only for a healthy baby but also for the mother's sustained health. There are two primary reasons why folic acid is indispensable in this preparation.

The Basics of Folic Acid: A Key Player in Cell Division and DNA Synthesis

Folic acid, a B vitamin, is a vital nutrient deeply involved in cell division, proliferation, and DNA synthesis. During pregnancy, a fetus's cells grow at an astonishing rate within the mother's body, requiring even more folic acid than usual.

Essential for Reducing the Risk of Neural Tube Defects (NTDs)

Folic acid's prominence in preconception care stems from its effectiveness in reducing the risk of Neural Tube Defects (NTDs) in babies.

The neural tube, which becomes the brain and spinal cord, closes by roughly 28 days after conception — around week 6 counting from the last menstrual period. In most cases this is complete before a pregnancy is recognised. That is why starting folic acid at the planning stage matters.

If you began taking it after that window, the reduction in neural tube defect risk is harder to achieve. But folic acid remains a nutrient you need during pregnancy, with a role in preventing anaemia among other things. Starting when you find out is still worth doing, and there is no reason to treat not having started earlier as a failing on your part.

Recommended Folic Acid Intake and Timing

So, how much folic acid should you take, and when should you start?

Recommended Intake by MHLW and WHO

Public health bodies such as Japan's Ministry of Health, Labour and Welfare (MHLW), the World Health Organization (WHO), and the Centers for Disease Control and Prevention (CDC) recommend that women planning pregnancy take 400 micrograms (mcg) of supplemental folic acid daily, in addition to their regular diet, to reduce the risk of NTDs. This is the amount advised to be supplemented, separate from dietary intake.

Ideal Intake Timing

The most effective timing for intake is to begin folic acid supplementation at least one month before planning conception, ideally 2 to 3 months prior, and continue throughout the first trimester of pregnancy (up to around week 12). This ensures that sufficient folic acid is accumulated in the body during the critical period when the neural tube is forming.

Food Sources vs. Supplements: The Role of Each

While folic acid is found in various foods, meeting the necessary amount solely through diet to reduce the risk of NTDs can be challenging.

Foods Rich in Folic Acid

Leafy Green Vegetables: Spinach, broccoli, asparagus, edamame, etc.
Legumes: Soybeans, natto (fermented soybeans), lentils, etc.
Liver: Chicken liver, pork liver, etc. (Note: Pregnant women should be cautious with liver intake due to potential vitamin A overdose).
Fruits: Strawberries, avocado, etc.

However, folic acid in food is water-soluble and heat-sensitive, meaning it can be lost during cooking. Furthermore, folic acid found in foods (polyglutamate form) has a lower absorption rate compared to folic acid found in supplements (monoglutamate form).

Supplementation is the Most Recommended and Reliable Method

Therefore, for the purpose of reducing the risk of neural tube defects, taking a folic acid supplement is recommended. Supplements allow you to take the recommended amount consistently, and they are better absorbed.

Upper limits and cautions

Supplemental folic acid (pteroylmonoglutamic acid) has an upper limit. Japan's dietary reference intakes set the tolerable upper intake level for supplemental folate at 900-1,000 μg per day depending on age. A 400 μg product once daily is enough; take care not to exceed the limit by stacking multivitamins or fortified foods on top of it.

Doses above 1 mg per day can mask the anaemia and neurological symptoms of vitamin B12 deficiency, so they should be used only on a doctor's instruction. If you take medication that affects folate metabolism (methotrexate, for example), or if you have previously had a child with a neural tube defect, the recommended dose differs — speak to your doctor.

Beyond Folic Acid: Comprehensive Preconception Care

Folic acid intake is just the beginning of preconception care. For a healthy pregnancy and delivery, many other factors should be considered:

Healthy Diet: A balanced diet, paying attention to other nutrients as needed.
Regular Exercise: Maintain a healthy weight and reduce stress.
Smoking Cessation and Moderate Alcohol Intake: If you're planning pregnancy, limit or avoid these as much as possible.
Weight Management: Being underweight or overweight can affect pregnancy.
Management of Chronic Conditions: If you have conditions like diabetes or thyroid disease, consult your doctor in advance.
Stress Reduction: Make time to relax both mentally and physically.

This book is dedicated to providing comprehensive health support and knowledge for women considering future pregnancies. Learn more about the book and how it can support your journey.

Frequently Asked Questions (FAQ)

Q1: How long should I continue taking folic acid?

A1: It's recommended to continue taking folic acid at least through the first trimester (up to around week 12 of pregnancy). This period is most crucial for reducing the risk of neural tube defects. Continuing throughout the mid and late stages of pregnancy can also help maintain maternal health, such as preventing anemia.

Q2: Are folic acid supplements truly necessary?

A2: For the purpose of reducing the risk of neural tube defects, supplements are recommended, since diet alone rarely provides enough. There is an upper limit, though: 400 μg once a day is sufficient. Take care not to exceed it by combining products.

A Message from Your Specialist

Pregnancy is a significant life event involving major changes for a woman's body. It's natural to feel anxious. However, with the right knowledge and proper preparation, you can confidently welcome this journey.

Taking folic acid is one of the simplest yet most profoundly valuable actions you can take for your future baby. Why not start incorporating folic acid into your preconception care today?

Empower yourself with knowledge to make informed decisions about your reproductive health and future. Dr. Takuma Sato's book, A Doctor's Guide to Women's Health & Preconception, offers comprehensive, evidence-based insights to help you navigate your journey with confidence.

What About Folic Acid for Men?

You may have seen the suggestion that couples should both take folic acid. For the male partner, a large trial found it made no difference.

In a multicentre randomized trial, 2,370 men whose partners were undergoing infertility treatment took 5 mg of folic acid plus 30 mg of zinc for six months. Live birth occurred in 34% of the supplement group and 35% of the placebo group — no difference (risk difference -0.9%, 95% CI -4.7% to 2.8%). Sperm concentration, motility, morphology, volume and total motile count were all unchanged. DNA fragmentation was in fact slightly higher (29.7% vs 27.2%), and abdominal discomfort, nausea and vomiting were more common than with placebo. The authors state that these findings do not support the use of folic acid and zinc supplementation by male partners (PMID: 31910279).

What does make a practical difference on the male side is not smoking, maintaining a healthy weight, limiting alcohol, and having a semen analysis done once.

References

Ministry of Health, Labour and Welfare of Japan. "Recommendations for Folic Acid Intake to Reduce the Risk of Neural Tube Defects and Folic Acid Intake from Regular Foods."
Centers for Disease Control and Prevention (CDC). Folic Acid.
Effect of Folic Acid and Zinc Supplementation in Men on Semen Quality and Live Birth Among Couples Undergoing Infertility Treatment: A Randomized Clinical Trial. JAMA. 2020. PMID: 31910279